Mariadb/MySQL數據庫單表查詢基本操做及DML語句
Mariadb/MySQL數據庫單表查詢基本操做及DML語句
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做者：尹正傑 node
版權聲明：原創做品，謝絕轉載！不然將追究法律責任。mysql
一數據庫及表相關概述正則表達式
1>.數據庫操做sql
建立數據庫： CREATE DATABASE|SCHEMA [IF NOT EXISTS] 'DB_NAME'; CHARACTER SET 'character set name’COLLATE 'collate name' 修改數據庫： ALTER DATABASE DB_NAME character set utf8; 刪除數據庫 DROP DATABASE|SCHEMA [IF EXISTS] 'DB_NAME'; 查看支持全部字符集： SHOW CHARACTER SET; 查看支持全部排序規則： SHOW COLLATION; 獲取命令使用幫助： HELP KEYWORD; 查看數據庫列表： SHOW DATABASES;
2>.建立表數據庫
建立表：CREATE TABLE (1) 直接建立 CREATE TABLE [IF NOT EXISTS] ‘tbl_name’ (col1 type1 修飾符, col2 type2 修飾符, ...) (2) 經過查詢現存表建立；新表會被直接插入查詢而來的數據 CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,...)] [table_options] [partition_options] select_statement (3) 經過複製現存的表的表結構建立，但不復制數據 CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name { LIKE old_tbl_name | (LIKE old_tbl_name) } 注意： Storage Engine是指表類型，也即在表建立時指明其使用的存儲引擎，同一庫中不一樣表可使用不一樣的存儲引擎 同一個庫中表建議要使用同一種存儲引擎類型 字段信息 col type1 PRIMARY KEY(col1,...) INDEX(col1, ...) UNIQUE KEY(col1, ...) 表選項： ENGINE [=] engine_name SHOW ENGINES;查看支持的engine類型 ROW_FORMAT [=] {DEFAULT|DYNAMIC|FIXED|COMPRESSED|REDUNDANT|COMPACT} 獲取幫助：
mysql> HELP CREATE TABLE;
3>.表操做express
表： 二維關係 設計表： 遵循規範 定義：字段，索引 字段：字段名，字段數據類型，修飾符 約束，索引：應該建立在常常用做查詢條件的字段上 查看全部的引擎： SHOW ENGINES 查看錶： SHOW TABLES [FROM db_name] 查看錶結構： DESC [db_name.]tb_name SHOW COLUMNS FROM [db_name.]tb_name 刪除表： DROP TABLE [IF EXISTS] tb_name ALTER TABLE 'tbl_name' 字段： 添加字段：add ADD col1 data_type [FIRST|AFTER col_name] 刪除字段：drop 修改字段： alter（默認值）, change（字段名）, modify（字段屬性） 索引: 添加索引：add index 刪除索引：drop index 表選項 修改: 查看錶上的索引： SHOW INDEXES FROM [db_name.]tbl_name; 查看幫助： Help ALTER TABLE
查看錶建立命令： SHOW CREATE TABLE tbl_name 查看錶狀態： SHOW TABLE STATUS LIKE 'tbl_name’ 查看庫中全部表狀態： SHOW TABLE STATUS FROM db_name
二.數據類型app
數據類型： 數據長什麼樣 數據須要多少空間來存放
系統內置數據類型和用戶定義數據類型
MySql支持多種列類型： 數值類型 日期/時間類型 字符串(字符)類型 更多數據類型說明參考:https://dev.mysql.com/doc/refman/5.5/en/data-types.html
選擇正確的數據類型對於得到高性能相當重要，三大原則： 更小的一般更好，儘可能使用可正確存儲數據的最小數據類型 簡單就好，簡單數據類型的操做一般須要更少的CPU週期 儘可能避免NULL，包含爲NULL的列，對MySQL更難優化
1>.整型ide
tinyint(m) 1個字節 範圍(-128~127) smallint(m) 2個字節 範圍(-32768~32767) mediumint(m) 3個字節 範圍(-8388608~8388607) int(m) 4個字節 範圍(-2147483648~2147483647) int(m)裏的m是表示SELECT查詢結果集中的顯示寬度，並不影響實際的取值範圍，規定了MySQL的一些交互工具（例如MySQL命令行客戶端）用來顯示字符的個數。對於存儲和計算來講，Int(1)和Int(20)是相同的 bigint(m) 8個字節 範圍(+-9.22*10的18次方) 加了unsigned，則最大值翻倍， 如：tinyint unsigned的取值範圍爲(0~255)
2>.布爾型工具
BOOL，BOOLEAN：布爾型，
是TINYINT(1)的同義詞。zero值被視爲假，非zero值視爲真
3>.浮點型(float和double)，近似值
float(m,d) 單精度浮點型 8位精度(4字節) m總個數，d小數位 double(m,d) 雙精度浮點型16位精度(8字節) m總個數，d小數位 設一個字段定義爲float(6,3)，若是插入一個數123.45678,實際數據庫裏存的是123.457，但總個數還以實際爲準，即6位
4>.定點數
在數據庫中存放的是精確值,存爲十進制
decimal(m,d) 參數m<65 是總個數，d<30且 d<m 是小數位
MySQL5.0和更高版本將數字打包保存到一個二進制字符串中（每4個字節存9個數字）。例如，decimal(18,9)小數點兩邊將各存儲9個數字，一共使用9個字節：小數點前的數字用4個字節，小數點後的數字用4個字節，小數點自己佔1個字節
浮點類型在存儲一樣範圍的值時，一般比decimal使用更少的空間。float使用4個字節存儲。double佔用8個字節
由於須要額外的空間和計算開銷，因此應該儘可能只在對小數進行精確計算時才使用decimal——例如存儲財務數據。但在數據量比較大的時候，能夠考慮使用bigint代替decimal
5>.字符串
char(n) 固定長度，最多255個字符 varchar(n) 可變長度，最多65535個字符 tinytext 可變長度，最多255個字符 text 可變長度，最多65535個字符 mediumtext 可變長度，最多2的24次方-1個字符 longtext 可變長度，最多2的32次方-1個字符 BINARY(M) 固定長度，可存二進制或字符，長度爲0-M字節 VARBINARY(M) 可變長度，可存二進制或字符，容許長度爲0-M字節 char和varchar： 1.char(n) 若存入字符數小於n，則以空格補於其後，查詢之時再將空格去掉，因此char類型存儲的字符串末尾不能有空格，varchar不限於此 2.char(n) 固定長度，char(4)不論是存入幾個字符，都將佔用4個字節，varchar是存入的實際字符數+1個字節（n< n>255)，因此varchar(4),存入3個字符將佔用4個字節 3.char類型的字符串檢索速度要比varchar類型的快 varchar和text： 1.varchar可指定n，text不能指定，內部存儲varchar是存入的實際字符數+1個字節（n< n>255)，text是實際字符數+2個字節。 2.text類型不能有默認值 3.varchar可直接建立索引，text建立索引要指定前多少個字符。varchar查詢速度快於text
6>.內建類型
ENUM枚舉, SET集合
7>.二進制數據：BLOB
BLOB和text存儲方式不一樣，TEXT以文本方式存儲，英文存儲區分大小寫，而Blob是以二進制方式存儲，不分大小寫
BLOB存儲的數據只能總體讀出
TEXT能夠指定字符集，BLOB不用指定字符集
8>.日期時間類型
date
日期 '2008-12-2'
time
時間 '12:25:36'
datetime
日期時間 '2008-12-2 22:06:44'
timestamp
自動存儲記錄修改時間
YEAR(2), YEAR(4)：
年份
timestamp
字段裏的時間數據會隨其餘字段修改的時候自動刷新，這個數據類型的字段能夠存放這條記錄最後被修改的時間
9>.修飾符
全部類型：
NULL
數據列可包含NULL值
NOT NULL
數據列不容許包含NULL值
DEFAULT
默認值
PRIMARY KEY
主鍵
UNIQUE KEY
惟一鍵
CHARACTER SET name
指定一個字符集
數值型
AUTO_INCREMENT
自動遞增，適用於整數類型
UNSIGNED
無符號
三.增
MariaDB [(none)]> help CREATE #查看CREATE命令的幫助信息 Many help items for your request exist. To make a more specific request, please type 'help <item>', where <item> is one of the following topics: CREATE DATABASE CREATE EVENT CREATE FUNCTION CREATE FUNCTION UDF CREATE INDEX CREATE PROCEDURE CREATE SERVER CREATE TABLE CREATE TABLESPACE CREATE TRIGGER CREATE USER CREATE VIEW SHOW SHOW CREATE DATABASE SHOW CREATE EVENT SHOW CREATE FUNCTION SHOW CREATE PROCEDURE SHOW CREATE TABLE SPATIAL MariaDB [(none)]> MariaDB [(none)]>
MariaDB [(none)]> HELP CREATE DATABASE #查看建立數據庫的命令 Name: 'CREATE DATABASE' Description: Syntax: CREATE {DATABASE | SCHEMA} [IF NOT EXISTS] db_name [create_specification] ... create_specification: [DEFAULT] CHARACTER SET [=] charset_name | [DEFAULT] COLLATE [=] collation_name CREATE DATABASE creates a database with the given name. To use this statement, you need the CREATE privilege for the database. CREATE SCHEMA is a synonym for CREATE DATABASE. URL: https://mariadb.com/kb/en/create-database/ MariaDB [(none)]> MariaDB [(none)]>
MariaDB [(none)]> HELP CREATE TABLE #查看建立表的命令幫助信息 Name: 'CREATE TABLE' Description: Syntax: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name (create_definition,...) [table_options] [partition_options] Or: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name [(create_definition,...)] [table_options] [partition_options] select_statement Or: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name { LIKE old_tbl_name | (LIKE old_tbl_name) } create_definition: col_name column_definition | [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ... | {INDEX|KEY} [index_name] [index_type] (index_col_name,...) [index_option] ... | [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY] [index_name] [index_type] (index_col_name,...) [index_option] ... | {FULLTEXT|SPATIAL} [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name,...) reference_definition | CHECK (expr) column_definition: data_type [NOT NULL | NULL] [DEFAULT default_value] [AUTO_INCREMENT] [UNIQUE [KEY] | [PRIMARY] KEY] [COMMENT 'string'] [COLUMN_FORMAT {FIXED|DYNAMIC|DEFAULT}] [STORAGE {DISK|MEMORY|DEFAULT}] [reference_definition] data_type: BIT[(length)] | TINYINT[(length)] [UNSIGNED] [ZEROFILL] | SMALLINT[(length)] [UNSIGNED] [ZEROFILL] | MEDIUMINT[(length)] [UNSIGNED] [ZEROFILL] | INT[(length)] [UNSIGNED] [ZEROFILL] | INTEGER[(length)] [UNSIGNED] [ZEROFILL] | BIGINT[(length)] [UNSIGNED] [ZEROFILL] | REAL[(length,decimals)] [UNSIGNED] [ZEROFILL] | DOUBLE[(length,decimals)] [UNSIGNED] [ZEROFILL] | FLOAT[(length,decimals)] [UNSIGNED] [ZEROFILL] | DECIMAL[(length[,decimals])] [UNSIGNED] [ZEROFILL] | NUMERIC[(length[,decimals])] [UNSIGNED] [ZEROFILL] | DATE | TIME | TIMESTAMP | DATETIME | YEAR | CHAR[(length)] [CHARACTER SET charset_name] [COLLATE collation_name] | VARCHAR(length) [CHARACTER SET charset_name] [COLLATE collation_name] | BINARY[(length)] | VARBINARY(length) | TINYBLOB | BLOB | MEDIUMBLOB | LONGBLOB | TINYTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | TEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | MEDIUMTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | LONGTEXT [BINARY] [CHARACTER SET charset_name] [COLLATE collation_name] | ENUM(value1,value2,value3,...) [CHARACTER SET charset_name] [COLLATE collation_name] | SET(value1,value2,value3,...) [CHARACTER SET charset_name] [COLLATE collation_name] | spatial_type index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH} index_option: KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name | COMMENT 'string' reference_definition: REFERENCES tbl_name (index_col_name,...) [MATCH FULL | MATCH PARTIAL | MATCH SIMPLE] [ON DELETE reference_option] [ON UPDATE reference_option] reference_option: RESTRICT | CASCADE | SET NULL | NO ACTION table_options: table_option [[,] table_option] ... table_option: ENGINE [=] engine_name | AUTO_INCREMENT [=] value | AVG_ROW_LENGTH [=] value | [DEFAULT] CHARACTER SET [=] charset_name | CHECKSUM [=] {0 | 1} | [DEFAULT] COLLATE [=] collation_name | COMMENT [=] 'string' | CONNECTION [=] 'connect_string' | DATA DIRECTORY [=] 'absolute path to directory' | DELAY_KEY_WRITE [=] {0 | 1} | INDEX DIRECTORY [=] 'absolute path to directory' | INSERT_METHOD [=] { NO | FIRST | LAST } | KEY_BLOCK_SIZE [=] value | MAX_ROWS [=] value | MIN_ROWS [=] value | PACK_KEYS [=] {0 | 1 | DEFAULT} | PASSWORD [=] 'string' | ROW_FORMAT [=] {DEFAULT|DYNAMIC|FIXED|COMPRESSED|REDUNDANT|COMPACT} | TABLESPACE tablespace_name [STORAGE {DISK|MEMORY|DEFAULT}] | UNION [=] (tbl_name[,tbl_name]...) partition_options: PARTITION BY { [LINEAR] HASH(expr) | [LINEAR] KEY(column_list) | RANGE{(expr) | COLUMNS(column_list)} | LIST{(expr) | COLUMNS(column_list)} } [PARTITIONS num] [SUBPARTITION BY { [LINEAR] HASH(expr) | [LINEAR] KEY(column_list) } [SUBPARTITIONS num] ] [(partition_definition [, partition_definition] ...)] partition_definition: PARTITION partition_name [VALUES {LESS THAN {(expr | value_list) | MAXVALUE} | IN (value_list)}] [[STORAGE] ENGINE [=] engine_name] [COMMENT [=] 'comment_text' ] [DATA DIRECTORY [=] 'data_dir'] [INDEX DIRECTORY [=] 'index_dir'] [MAX_ROWS [=] max_number_of_rows] [MIN_ROWS [=] min_number_of_rows] [TABLESPACE [=] tablespace_name] [NODEGROUP [=] node_group_id] [(subpartition_definition [, subpartition_definition] ...)] subpartition_definition: SUBPARTITION logical_name [[STORAGE] ENGINE [=] engine_name] [COMMENT [=] 'comment_text' ] [DATA DIRECTORY [=] 'data_dir'] [INDEX DIRECTORY [=] 'index_dir'] [MAX_ROWS [=] max_number_of_rows] [MIN_ROWS [=] min_number_of_rows] [TABLESPACE [=] tablespace_name] [NODEGROUP [=] node_group_id] select_statement: [IGNORE | REPLACE] [AS] SELECT ... (Some valid select statement) CREATE TABLE creates a table with the given name. You must have the CREATE privilege for the table. Rules for permissible table names are given in https://mariadb.com/kb/en/identifier-names/. By default, the table is created in the default database, using the InnoDB storage engine. An error occurs if the table exists, if there is no default database, or if the database does not exist. URL: https://mariadb.com/kb/en/create-table/ MariaDB [(none)]>
MariaDB [yinzhengjie]> HELP INSERT #查看往表中插入數據的命令幫助信息 Name: 'INSERT' Description: Syntax: INSERT [LOW_PRIORITY | DELAYED | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name [(col_name,...)] {VALUES | VALUE} ({expr | DEFAULT},...),(...),... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] Or: INSERT [LOW_PRIORITY | DELAYED | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name SET col_name={expr | DEFAULT}, ... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] Or: INSERT [LOW_PRIORITY | HIGH_PRIORITY] [IGNORE] [INTO] tbl_name [(col_name,...)] SELECT ... [ ON DUPLICATE KEY UPDATE col_name=expr [, col_name=expr] ... ] INSERT inserts new rows into an existing table. The INSERT ... VALUES and INSERT ... SET forms of the statement insert rows based on explicitly specified values. The INSERT ... SELECT form inserts rows selected from another table or tables. INSERT ... SELECT is discussed further in [HELP INSERT SELECT]. URL: https://mariadb.com/kb/en/insert/ MariaDB [yinzhengjie]>
1>.建立一個名稱爲"yinzhengjie"的數據庫
MariaDB [(none)]> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | +--------------------+ 3 rows in set (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> CREATE DATABASE yinzhengjie; #建立一個名稱爲"yinzhengjie"的數據庫 Query OK, 1 row affected (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | yinzhengjie | +--------------------+ 4 rows in set (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> CREATE DATABASE IF NOT EXISTS yinzhengjie; #建立數據庫時若不存在同名數據庫則建立，已存在則不建立。 Query OK, 0 rows affected, 1 warning (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | yinzhengjie | +--------------------+ 4 rows in set (0.00 sec) MariaDB [(none)]>
[root@node105.yinzhengjie.org.cn ~]# cat /mysql/3306/data/yinzhengjie/db.opt #建立數據庫成功後，在數據庫對應的系統目錄會自動生成該文件 default-character-set=latin1 #默認的字符集 default-collation=latin1_swedish_ci #默認的字符集排序規則 [root@node105.yinzhengjie.org.cn ~]#
2>.建立數據庫時指定字符集
MariaDB [(none)]> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | yinzhengjie | +--------------------+ rows in set (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> CREATE SCHEMA IF NOT EXISTS yinzhengjie2019 DEFAULT CHARACTER SET = utf8mb4; #utf8mb4支持比utf8更多的字符，包括表情包之類的數據。 Query OK, 1 row affected (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | yinzhengjie | | yinzhengjie2019 | +--------------------+ rows in set (0.00 sec) MariaDB [(none)]>
[root@node105.yinzhengjie.org.cn ~]# cat /mysql/3306/data/yinzhengjie2019/db.opt default-character-set=utf8mb4 default-collation=utf8mb4_general_ci [root@node105.yinzhengjie.org.cn ~]#
3>.在"yinzhengjie"數據庫中建立一張"students"表
MariaDB [(none)]> use yinzhengjie Database changed MariaDB [yinzhengjie]> show tables; #當前數據庫中尚未任何表 Empty set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> CREATE TABLE students(id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,name VARCHAR(30) NOT NULL,sex ENUM('boy','girl') DEFAULT 'boy',age TINYINT UNSIGNED,mobile CHAR(11),address VARCHAR(50)); Query OK, 0 rows affected (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SHOW TABLES; #表建立成功後，咱們就會在當前數據庫看到對應的students表啦 +-----------------------+ | Tables_in_yinzhengjie | +-----------------------+ | students | +-----------------------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> DESC students; #查看錶結構 +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.01 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SHOW COLUMNS FROM students; #和上面的命令等效，也能夠查看錶結構 +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
4>.往"students"表中插入數據
MariaDB [yinzhengjie]> SELECT COUNT(*) FROM students; +----------+ | COUNT(*) | +----------+ | 0 | +----------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> DESC students; +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> INSERT INTO students (name,age,mobile,address) VALUES ('Jason Yin',18,10000,'beijing'),('Jay','40',10086,'Taiwan'); Query OK, 2 rows affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT COUNT(*) FROM students; +----------+ | COUNT(*) | +----------+ | 2 | +----------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> DESC students; +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> INSERT INTO students SET name='yinzhengjie',age=27,address='shanxi'; Query OK, 1 row affected (0.01 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students; +----+-------------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-------------+------+------+--------+---------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 3 | yinzhengjie | boy | 27 | NULL | shanxi | +----+-------------+------+------+--------+---------+ 3 rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+-------------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-------------+------+------+--------+---------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 3 | yinzhengjie | boy | 27 | NULL | shanxi | +----+-------------+------+------+--------+---------+ 3 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> INSERT students (age,sex,name,mobile,address) VALUES (28,'girl','Gloria Tang Tsz-Kei',null,'Hong Kong'); Query OK, 1 row affected (0.01 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+--------+-----------+ | id | name | sex | age | mobile | address | +----+---------------------+------+------+--------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 3 | yinzhengjie | boy | 27 | NULL | shanxi | | 4 | Gloria Tang Tsz-Kei | girl | 28 | NULL | Hong Kong | +----+---------------------+------+------+--------+-----------+ 4 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> DESC students; +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> DESC custom; +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+--------+-----------+ | id | name | sex | age | mobile | address | +----+---------------------+------+------+--------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 3 | yinzhengjie | boy | 27 | NULL | shanxi | | 4 | Gloria Tang Tsz-Kei | girl | 28 | NULL | Hong Kong | +----+---------------------+------+------+--------+-----------+ 4 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM custom; Empty set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> INSERT custom SELECT * FROM students; #將一張表的查詢結果插入到另一張表，前提是兩張表結構要一致! Query OK, 4 rows affected (0.01 sec) Records: 4 Duplicates: 0 Warnings: 0 MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM custom; +----+---------------------+------+------+--------+-----------+ | id | name | sex | age | mobile | address | +----+---------------------+------+------+--------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 3 | yinzhengjie | boy | 27 | NULL | shanxi | | 4 | Gloria Tang Tsz-Kei | girl | 28 | NULL | Hong Kong | +----+---------------------+------+------+--------+-----------+ 4 rows in set (0.00 sec) MariaDB [yinzhengjie]>
5>.用已經存在的表建立出一張新表(複製內容，表結構屬性不徹底複製)
MariaDB [yinzhengjie]> DESC students; #注意該表是有主鍵的 +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> CREATE TABLE employee SELECT * FROM students; #將students的內容克隆到employee表中。 Query OK, 2 rows affected (0.01 sec) Records: 2 Duplicates: 0 Warnings: 0 MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> DESC employee; #克隆出來的表是沒有主鍵的。 +---------+---------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+-------+ | id | int(10) unsigned | NO | | 0 | | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+-------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM employee; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
6>.用已經存在的表建立出一張新表(僅僅複製表結構，不復制內容)
MariaDB [yinzhengjie]> DESC students; +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> CREATE TABLE custom LIKE students; #僅僅將students表結構複製給custom表 Query OK, 0 rows affected (0.01 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> DESC custom; +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM custom; Empty set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
7>.
四.刪
MariaDB [(none)]> help DROP #查看DROP命令的幫助信息 Many help items for your request exist. To make a more specific request, please type 'help <item>', where <item> is one of the following topics: ALTER TABLE ALTER TABLESPACE DEALLOCATE PREPARE DROP DATABASE DROP EVENT DROP FUNCTION DROP FUNCTION UDF DROP INDEX DROP PROCEDURE DROP SERVER DROP TABLE DROP TABLESPACE DROP TRIGGER DROP USER DROP VIEW MariaDB [(none)]>
MariaDB [(none)]> help DELETE #查看DELETE命令的幫助信息 Name: 'DELETE' Description: Syntax: Single-table syntax: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name [WHERE where_condition] [ORDER BY ...] [LIMIT row_count] Multiple-table syntax: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] tbl_name[.*] [, tbl_name[.*]] ... FROM table_references [WHERE where_condition] Or: DELETE [LOW_PRIORITY] [QUICK] [IGNORE] FROM tbl_name[.*] [, tbl_name[.*]] ... USING table_references [WHERE where_condition] For the single-table syntax, the DELETE statement deletes rows from tbl_name and returns a count of the number of deleted rows. This count can be obtained by calling the ROW_COUNT() function (see https://mariadb.com/kb/en/information-functions-row_count/). The WHERE clause, if given, specifies the conditions that identify which rows to delete. With no WHERE clause, all rows are deleted. If the ORDER BY clause is specified, the rows are deleted in the order that is specified. The LIMIT clause places a limit on the number of rows that can be deleted. For the multiple-table syntax, DELETE deletes from each tbl_name the rows that satisfy the conditions. In this case, ORDER BY and LIMIT cannot be used. where_condition is an expression that evaluates to true for each row to be deleted. It is specified as described in https://mariadb.com/kb/en/select/. Currently, you cannot delete from a table and select from the same table in a subquery. You need the DELETE privilege on a table to delete rows from it. You need only the SELECT privilege for any columns that are only read, such as those named in the WHERE clause. As stated, a DELETE statement with no WHERE clause deletes all rows. A faster way to do this, when you do not need to know the number of deleted rows, is to use TRUNCATE TABLE. However, within a transaction or if you have a lock on the table, TRUNCATE TABLE cannot be used whereas DELETE can. See [HELP TRUNCATE TABLE], and [HELP LOCK]. URL: https://mariadb.com/kb/en/delete/ MariaDB [(none)]>
1>.刪除指定數據庫
MariaDB [(none)]> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | yinzhengjie | | yinzhengjie2019 | +--------------------+ 5 rows in set (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> DROP DATABASE IF EXISTS yinzhengjie2019; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | yinzhengjie | +--------------------+ 4 rows in set (0.00 sec) MariaDB [(none)]>
2>.刪除表
MariaDB [yinzhengjie]> SHOW TABLES; +-----------------------+ | Tables_in_yinzhengjie | +-----------------------+ | students | +-----------------------+ row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> DROP TABLE IF EXISTS students; Query OK, 0 rows affected (0.01 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SHOW TABLES; Empty set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
3>.刪除表中的記錄
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+--------+-----------+ | id | name | sex | age | mobile | address | +----+---------------------+------+------+--------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 3 | yinzhengjie | boy | 27 | NULL | shanxi | | 4 | Gloria Tang Tsz-Kei | girl | 28 | NULL | Hong Kong | +----+---------------------+------+------+--------+-----------+ 4 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> DELETE FROM students WHERE id >= 3; #刪除id列大於3的行，切記要用where語句過濾匹配的行！ Query OK, 2 rows affected (0.01 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
4>. 使用TRUNCATE命令快速清空一張表
MariaDB [yinzhengjie]> SELECT * FROM custom; +----+---------------------+------+------+--------+-----------+ | id | name | sex | age | mobile | address | +----+---------------------+------+------+--------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 3 | yinzhengjie | boy | 27 | NULL | shanxi | | 4 | Gloria Tang Tsz-Kei | girl | 28 | NULL | Hong Kong | +----+---------------------+------+------+--------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> TRUNCATE TABLE custom; #快速清空一張表的數據，該操做將沒法恢復！快速刪除大表數據的確快但請慎用! Query OK, 0 rows affected (0.01 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM custom; Empty set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
五.改
MariaDB [yinzhengjie]> HELP ALTER TABLE; #查看修改表結構命令的幫助信息 Name: 'ALTER TABLE' Description: Syntax: ALTER [ONLINE | OFFLINE] [IGNORE] TABLE tbl_name [alter_specification [, alter_specification] ...] [partition_options] alter_specification: table_options | ADD [COLUMN] col_name column_definition [FIRST | AFTER col_name ] | ADD [COLUMN] (col_name column_definition,...) | ADD {INDEX|KEY} [index_name] [index_type] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY] [index_name] [index_type] (index_col_name,...) [index_option] ... | ADD FULLTEXT [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | ADD SPATIAL [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name,...) reference_definition | ALTER [COLUMN] col_name {SET DEFAULT literal | DROP DEFAULT} | CHANGE [COLUMN] old_col_name new_col_name column_definition [FIRST|AFTER col_name] | MODIFY [COLUMN] col_name column_definition [FIRST | AFTER col_name] | DROP [COLUMN] col_name | DROP PRIMARY KEY | DROP {INDEX|KEY} index_name | DROP FOREIGN KEY fk_symbol | MAX_ROWS = rows | DISABLE KEYS | ENABLE KEYS | RENAME [TO|AS] new_tbl_name | ORDER BY col_name [, col_name] ... | CONVERT TO CHARACTER SET charset_name [COLLATE collation_name] | [DEFAULT] CHARACTER SET [=] charset_name [COLLATE [=] collation_name] | DISCARD TABLESPACE | IMPORT TABLESPACE | FORCE | ADD PARTITION (partition_definition) | DROP PARTITION partition_names | TRUNCATE PARTITION {partition_names | ALL} | COALESCE PARTITION number | REORGANIZE PARTITION [partition_names INTO (partition_definitions)] | ANALYZE PARTITION {partition_names | ALL} | CHECK PARTITION {partition_names | ALL} | OPTIMIZE PARTITION {partition_names | ALL} | REBUILD PARTITION {partition_names | ALL} | REPAIR PARTITION {partition_names | ALL} | PARTITION BY partitioning_expression | REMOVE PARTITIONING index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH} index_option: KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name | COMMENT 'string' table_options: table_option [[,] table_option] ... (see CREATE TABLE options) partition_options: (see CREATE TABLE options) ALTER TABLE changes the structure of a table. For example, you can add or delete columns, create or destroy indexes, change the type of existing columns, or rename columns or the table itself. You can also change characteristics such as the storage engine used for the table or the table comment. Partitioning-related clauses for ALTER TABLE can be used with partitioned tables for repartitioning, for adding, dropping, merging, and splitting partitions, and for performing partitioning maintenance. For more information, see http://dev.mysql.com/doc/refman/5.5/en/alter-table-partition-operations .html. Following the table name, specify the alterations to be made. If none are given, ALTER TABLE does nothing. URL: https://mariadb.com/kb/en/alter-table/ MariaDB [yinzhengjie]>
MariaDB [(none)]> help UPDATE #查看UPDATE命令的幫助信息 Name: 'UPDATE' Description: Syntax: Single-table syntax: UPDATE [LOW_PRIORITY] [IGNORE] table_reference SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ... [WHERE where_condition] [ORDER BY ...] [LIMIT row_count] Multiple-table syntax: UPDATE [LOW_PRIORITY] [IGNORE] table_references SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ... [WHERE where_condition] For the single-table syntax, the UPDATE statement updates columns of existing rows in the named table with new values. The SET clause indicates which columns to modify and the values they should be given. Each value can be given as an expression, or the keyword DEFAULT to set a column explicitly to its default value. The WHERE clause, if given, specifies the conditions that identify which rows to update. With no WHERE clause, all rows are updated. If the ORDER BY clause is specified, the rows are updated in the order that is specified. The LIMIT clause places a limit on the number of rows that can be updated. For the multiple-table syntax, UPDATE updates rows in each table named in table_references that satisfy the conditions. In this case, ORDER BY and LIMIT cannot be used. where_condition is an expression that evaluates to true for each row to be updated. For expression syntax, see http://dev.mysql.com/doc/refman/5.5/en/expressions.html. table_references and where_condition are is specified as described in https://mariadb.com/kb/en/select/. You need the UPDATE privilege only for columns referenced in an UPDATE that are actually updated. You need only the SELECT privilege for any columns that are read but not modified. The UPDATE statement supports the following modifiers: o With the LOW_PRIORITY keyword, execution of the UPDATE is delayed until no other clients are reading from the table. This affects only storage engines that use only table-level locking (such as MyISAM, MEMORY, and MERGE). o With the IGNORE keyword, the update statement does not abort even if errors occur during the update. Rows for which duplicate-key conflicts occur are not updated. Rows for which columns are updated to values that would cause data conversion errors are updated to the closest valid values instead. URL: https://mariadb.com/kb/en/update/ MariaDB [(none)]>
1>.修改表的字符集
MariaDB [yinzhengjie]> SHOW CREATE TABLE students; +----------+------------------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table |+----------+------------------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+| students | CREATE TABLE `students` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(30) NOT NULL, `sex` enum('boy','girl') DEFAULT 'boy', `age` tinyint(3) unsigned DEFAULT NULL, `mobile` char(11) DEFAULT NULL, `address` varchar(50) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1 | +----------+------------------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+1 row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> ALTER TABLE students CHARACTER SET = utf8mb4; #推薦使用utf8mb4字符集，它能夠比utf8支持更多的字符 Query OK, 0 rows affected (0.00 sec) Records: 0 Duplicates: 0 Warnings: 0 MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SHOW CREATE TABLE students\G *************************** 1. row *************************** Table: students Create Table: CREATE TABLE `students` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(30) CHARACTER SET latin1 NOT NULL, `sex` enum('boy','girl') CHARACTER SET latin1 DEFAULT 'boy', `age` tinyint(3) unsigned DEFAULT NULL, `mobile` char(11) CHARACTER SET latin1 DEFAULT NULL, `address` varchar(50) CHARACTER SET latin1 DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb4 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
2>.修改表中某個字段的值
MariaDB [yinzhengjie]> SELECT * FROM students; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> UPDATE students SET age=27 WHERE id = 1; Query OK, 1 row affected (0.00 sec) Rows matched: 1 Changed: 1 Warnings: 0 MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | address | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
3>.數據庫字符集更改
MariaDB [yinzhengjie]> SHOW CREATE DATABASE yinzhengjie; +-------------+------------------------------------------------------------------------+ | Database | Create Database | +-------------+------------------------------------------------------------------------+ | yinzhengjie | CREATE DATABASE `yinzhengjie` /*!40100 DEFAULT CHARACTER SET latin1 */ | +-------------+------------------------------------------------------------------------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> ALTER DATABASE yinzhengjie CHARACTER SET utf8mb4; Query OK, 1 row affected (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SHOW CREATE DATABASE yinzhengjie; +-------------+-------------------------------------------------------------------------+ | Database | Create Database | +-------------+-------------------------------------------------------------------------+ | yinzhengjie | CREATE DATABASE `yinzhengjie` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ | +-------------+-------------------------------------------------------------------------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
4>.表的字符集更改（隻影響新添加字段，已添加字段在字符集不變）
MariaDB [yinzhengjie]> SHOW CREATE TABLE students\G *************************** 1. row *************************** Table: students Create Table: CREATE TABLE `students` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(30) CHARACTER SET latin1 NOT NULL, `sex` enum('boy','girl') CHARACTER SET latin1 DEFAULT 'boy', `age` tinyint(3) unsigned DEFAULT NULL, `mobile` char(11) CHARACTER SET latin1 DEFAULT NULL, `address` varchar(50) CHARACTER SET latin1 DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb4 1 row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> ALTER TABLE students CHARACTER SET utf8; Query OK, 0 rows affected (0.00 sec) Records: 0 Duplicates: 0 Warnings: 0 MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SHOW CREATE TABLE students\G *************************** 1. row *************************** Table: students Create Table: CREATE TABLE `students` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(30) CHARACTER SET latin1 NOT NULL, `sex` enum('boy','girl') CHARACTER SET latin1 DEFAULT 'boy', `age` tinyint(3) unsigned DEFAULT NULL, `mobile` char(11) CHARACTER SET latin1 DEFAULT NULL, `address` varchar(50) CHARACTER SET latin1 DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
5>.表中某個字段的字符集更改
MariaDB [yinzhengjie]> SHOW CREATE TABLE students\G *************************** 1. row *************************** Table: students Create Table: CREATE TABLE `students` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(30) CHARACTER SET latin1 NOT NULL, `sex` enum('boy','girl') CHARACTER SET latin1 DEFAULT 'boy', `age` tinyint(3) unsigned DEFAULT NULL, `mobile` char(11) CHARACTER SET latin1 DEFAULT NULL, `address` varchar(50) CHARACTER SET latin1 DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 1 row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> ALTER TABLE students CHANGE name name VARCHAR(50) CHARACTER SET utf8mb4; Query OK, 2 rows affected (0.02 sec) Records: 2 Duplicates: 0 Warnings: 0 MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> ALTER TABLE students CHANGE address adress VARCHAR(100) CHARACTER SET utf8mb4; Query OK, 2 rows affected (0.02 sec) Records: 2 Duplicates: 0 Warnings: 0 MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SHOW CREATE TABLE students\G *************************** 1. row *************************** Table: students Create Table: CREATE TABLE `students` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(50) CHARACTER SET utf8mb4 DEFAULT NULL, `sex` enum('boy','girl') CHARACTER SET latin1 DEFAULT 'boy', `age` tinyint(3) unsigned DEFAULT NULL, `mobile` char(11) CHARACTER SET latin1 DEFAULT NULL, `adress` varchar(100) CHARACTER SET utf8mb4 DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
6>.
六.查
MariaDB [mysql]> HELP SHOW #查看SHOW命令的幫助信息 Name: 'SHOW' Description: SHOW has many forms that provide information about databases, tables, columns, or status information about the server. This section describes those following: SHOW AUTHORS SHOW {BINARY | MASTER} LOGS SHOW BINLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count] SHOW CHARACTER SET [like_or_where] SHOW COLLATION [like_or_where] SHOW [FULL] COLUMNS FROM tbl_name [FROM db_name] [like_or_where] SHOW CONTRIBUTORS SHOW CREATE DATABASE db_name SHOW CREATE EVENT event_name SHOW CREATE FUNCTION func_name SHOW CREATE PROCEDURE proc_name SHOW CREATE TABLE tbl_name SHOW CREATE TRIGGER trigger_name SHOW CREATE VIEW view_name SHOW DATABASES [like_or_where] SHOW ENGINE engine_name {STATUS | MUTEX} SHOW [STORAGE] ENGINES SHOW ERRORS [LIMIT [offset,] row_count] SHOW EVENTS SHOW FUNCTION CODE func_name SHOW FUNCTION STATUS [like_or_where] SHOW GRANTS FOR user SHOW INDEX FROM tbl_name [FROM db_name] SHOW MASTER STATUS SHOW OPEN TABLES [FROM db_name] [like_or_where] SHOW PLUGINS SHOW PROCEDURE CODE proc_name SHOW PROCEDURE STATUS [like_or_where] SHOW PRIVILEGES SHOW [FULL] PROCESSLIST SHOW PROFILE [types] [FOR QUERY n] [OFFSET n] [LIMIT n] SHOW PROFILES SHOW SLAVE HOSTS SHOW SLAVE STATUS SHOW [GLOBAL | SESSION] STATUS [like_or_where] SHOW TABLE STATUS [FROM db_name] [like_or_where] SHOW [FULL] TABLES [FROM db_name] [like_or_where] SHOW TRIGGERS [FROM db_name] [like_or_where] SHOW [GLOBAL | SESSION] VARIABLES [like_or_where] SHOW WARNINGS [LIMIT [offset,] row_count] like_or_where: LIKE 'pattern' | WHERE expr If the syntax for a given SHOW statement includes a LIKE 'pattern' part, 'pattern' is a string that can contain the SQL "%" and "_" wildcard characters. The pattern is useful for restricting statement output to matching values. Several SHOW statements also accept a WHERE clause that provides more flexibility in specifying which rows to display. See http://dev.mysql.com/doc/refman/5.5/en/extended-show.html. URL: http://dev.mysql.com/doc/refman/5.5/en/show.html MariaDB [mysql]>
MariaDB [(none)]> help SELECT #查看SELECT命令的幫助信息 Name: 'SELECT' Description: Syntax: SELECT [ALL | DISTINCT | DISTINCTROW ] [HIGH_PRIORITY] [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT] [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS] select_expr [, select_expr ...] [FROM table_references [WHERE where_condition] [GROUP BY {col_name | expr | position} [ASC | DESC], ... [WITH ROLLUP]] [HAVING where_condition] [ORDER BY {col_name | expr | position} [ASC | DESC], ...] [LIMIT {[offset,] row_count | row_count OFFSET offset}] [PROCEDURE procedure_name(argument_list)] [INTO OUTFILE 'file_name' [CHARACTER SET charset_name] export_options | INTO DUMPFILE 'file_name' | INTO var_name [, var_name]] [FOR UPDATE | LOCK IN SHARE MODE]] SELECT is used to retrieve rows selected from one or more tables, and can include UNION statements and subqueries. See [HELP UNION], and https://mariadb.com/kb/en/subqueries/. The most commonly used clauses of SELECT statements are these: o Each select_expr indicates a column that you want to retrieve. There must be at least one select_expr. o table_references indicates the table or tables from which to retrieve rows. Its syntax is described in [HELP JOIN]. o The WHERE clause, if given, indicates the condition or conditions that rows must satisfy to be selected. where_condition is an expression that evaluates to true for each row to be selected. The statement selects all rows if there is no WHERE clause. In the WHERE expression, you can use any of the functions and operators that MySQL supports, except for aggregate (summary) functions. See https://mariadb.com/kb/en/select#select-expressions, and https://mariadb.com/kb/en/functions-and-operators/. SELECT can also be used to retrieve rows computed without reference to any table. URL: https://mariadb.com/kb/en/select/ MariaDB [(none)]>
1>.查看現有數據庫
[root@node102.yinzhengjie.org.cn ~]# mysql Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 16 Server version: 5.5.64-MariaDB MariaDB Server Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> MariaDB [(none)]> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | #該數據庫在內存中存放，所以咱們在MySQL數據存儲目錄中找不到該目錄名稱，但下面3個目錄是能夠看到的。 | mysql | | performance_schema | | test | +--------------------+ rows in set (0.00 sec) MariaDB [(none)]>
2>.查看數據庫版本
MariaDB [(none)]> SELECT VERSION(); +----------------+ | VERSION() | +----------------+ | 5.5.64-MariaDB | +----------------+ 1 row in set (0.00 sec) MariaDB [(none)]>
3>.查看當前登陸用戶信息
MariaDB [(none)]> SELECT USER(); +----------------+ | USER() | +----------------+ | root@localhost | +----------------+ 1 row in set (0.00 sec) MariaDB [(none)]>
4>.查看當前所在數據庫
MariaDB [(none)]> SELECT DATABASE(); +------------+ | DATABASE() | +------------+ | NULL | +------------+ 1 row in set (0.00 sec) MariaDB [(none)]> MariaDB [(none)]> USE mysql Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed MariaDB [mysql]> MariaDB [mysql]> SELECT DATABASE(); +------------+ | DATABASE() | +------------+ | mysql | +------------+ 1 row in set (0.00 sec) MariaDB [mysql]> MariaDB [mysql]>
5>.查看當前所在數據庫中存在的表
MariaDB [mysql]> SHOW TABLES; +---------------------------+ | Tables_in_mysql | +---------------------------+ | columns_priv | | db | | event | | func | | general_log | | help_category | | help_keyword | | help_relation | | help_topic | | host | | ndb_binlog_index | | plugin | | proc | | procs_priv | | proxies_priv | | servers | | slow_log | | tables_priv | | time_zone | | time_zone_leap_second | | time_zone_name | | time_zone_transition | | time_zone_transition_type | | user | +---------------------------+ 24 rows in set (0.00 sec) MariaDB [mysql]>
[root@node102.yinzhengjie.org.cn ~]# ll /var/lib/mysql/mysql #數據庫的本質對應Linux就是一個文件夾 total 1000 -rw-rw---- 1 mysql mysql 8820 Oct 25 06:26 columns_priv.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 columns_priv.MYD -rw-rw---- 1 mysql mysql 4096 Oct 25 06:26 columns_priv.MYI -rw-rw---- 1 mysql mysql 9582 Oct 25 06:26 db.frm -rw-rw---- 1 mysql mysql 880 Oct 25 06:26 db.MYD -rw-rw---- 1 mysql mysql 5120 Oct 25 06:26 db.MYI -rw-rw---- 1 mysql mysql 10239 Oct 25 06:26 event.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 event.MYD -rw-rw---- 1 mysql mysql 2048 Oct 25 06:26 event.MYI -rw-rw---- 1 mysql mysql 8665 Oct 25 06:26 func.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 func.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 func.MYI -rw-rw---- 1 mysql mysql 35 Oct 25 06:26 general_log.CSM -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 general_log.CSV -rw-rw---- 1 mysql mysql 8776 Oct 25 06:26 general_log.frm -rw-rw---- 1 mysql mysql 8700 Oct 25 06:26 help_category.frm -rw-rw---- 1 mysql mysql 1092 Oct 25 06:26 help_category.MYD -rw-rw---- 1 mysql mysql 3072 Oct 25 06:26 help_category.MYI -rw-rw---- 1 mysql mysql 8612 Oct 25 06:26 help_keyword.frm -rw-rw---- 1 mysql mysql 91408 Oct 25 06:26 help_keyword.MYD -rw-rw---- 1 mysql mysql 16384 Oct 25 06:26 help_keyword.MYI -rw-rw---- 1 mysql mysql 8630 Oct 25 06:26 help_relation.frm -rw-rw---- 1 mysql mysql 9252 Oct 25 06:26 help_relation.MYD -rw-rw---- 1 mysql mysql 19456 Oct 25 06:26 help_relation.MYI -rw-rw---- 1 mysql mysql 8770 Oct 25 06:26 help_topic.frm -rw-rw---- 1 mysql mysql 450388 Oct 25 06:26 help_topic.MYD -rw-rw---- 1 mysql mysql 20480 Oct 25 06:26 help_topic.MYI -rw-rw---- 1 mysql mysql 9510 Oct 25 06:26 host.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 host.MYD -rw-rw---- 1 mysql mysql 2048 Oct 25 06:26 host.MYI -rw-rw---- 1 mysql mysql 8778 Oct 25 06:26 ndb_binlog_index.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 ndb_binlog_index.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 ndb_binlog_index.MYI -rw-rw---- 1 mysql mysql 8586 Oct 25 06:26 plugin.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 plugin.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 plugin.MYI -rw-rw---- 1 mysql mysql 10012 Oct 25 06:26 proc.frm -rw-rw---- 1 mysql mysql 292 Oct 25 06:26 proc.MYD -rw-rw---- 1 mysql mysql 4096 Oct 25 06:26 proc.MYI -rw-rw---- 1 mysql mysql 8875 Oct 25 06:26 procs_priv.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 procs_priv.MYD -rw-rw---- 1 mysql mysql 4096 Oct 25 06:26 procs_priv.MYI -rw-rw---- 1 mysql mysql 8800 Oct 25 06:26 proxies_priv.frm -rw-rw---- 1 mysql mysql 1386 Oct 25 06:26 proxies_priv.MYD -rw-rw---- 1 mysql mysql 5120 Oct 25 06:26 proxies_priv.MYI -rw-rw---- 1 mysql mysql 8838 Oct 25 06:26 servers.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 servers.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 servers.MYI -rw-rw---- 1 mysql mysql 35 Oct 25 06:26 slow_log.CSM -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 slow_log.CSV -rw-rw---- 1 mysql mysql 8976 Oct 25 06:26 slow_log.frm -rw-rw---- 1 mysql mysql 8955 Oct 25 06:26 tables_priv.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 tables_priv.MYD -rw-rw---- 1 mysql mysql 4096 Oct 25 06:26 tables_priv.MYI -rw-rw---- 1 mysql mysql 8636 Oct 25 06:26 time_zone.frm -rw-rw---- 1 mysql mysql 8624 Oct 25 06:26 time_zone_leap_second.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 time_zone_leap_second.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 time_zone_leap_second.MYI -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 time_zone.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 time_zone.MYI -rw-rw---- 1 mysql mysql 8606 Oct 25 06:26 time_zone_name.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 time_zone_name.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 time_zone_name.MYI -rw-rw---- 1 mysql mysql 8686 Oct 25 06:26 time_zone_transition.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 time_zone_transition.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 time_zone_transition.MYI -rw-rw---- 1 mysql mysql 8748 Oct 25 06:26 time_zone_transition_type.frm -rw-rw---- 1 mysql mysql 0 Oct 25 06:26 time_zone_transition_type.MYD -rw-rw---- 1 mysql mysql 1024 Oct 25 06:26 time_zone_transition_type.MYI -rw-rw---- 1 mysql mysql 10630 Oct 25 06:26 user.frm -rw-rw---- 1 mysql mysql 340 Oct 25 06:26 user.MYD -rw-rw---- 1 mysql mysql 2048 Oct 25 06:26 user.MYI [root@node102.yinzhengjie.org.cn ~]#
6>.查看錶字段(列名)信息
MariaDB [yinzhengjie]> DESC students; +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.01 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SHOW COLUMNS FROM students; +---------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+---------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | name | varchar(30) | NO | | NULL | | | sex | enum('boy','girl') | YES | | boy | | | age | tinyint(3) unsigned | YES | | NULL | | | mobile | char(11) | YES | | NULL | | | address | varchar(50) | YES | | NULL | | +---------+---------------------+------+-----+---------+----------------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
7>.查看mysql數據庫user表的部分字段
MariaDB [mysql]> SELECT host,user,password FROM user; +----------------------------+------+----------+ | host | user | password | +----------------------------+------+----------+ | localhost | root | | | node102.yinzhengjie.org.cn | root | | | 127.0.0.1 | root | | | ::1 | root | | | localhost | | | | node102.yinzhengjie.org.cn | | | +----------------------------+------+----------+ 6 rows in set (0.00 sec) MariaDB [mysql]>
8>.顯示當前系統時間
MariaDB [mysql]> SELECT NOW(); +---------------------+ | NOW() | +---------------------+ | 2019-10-25 10:07:42 | +---------------------+ 1 row in set (0.00 sec) MariaDB [mysql]>
9>.查看MySQL配置文件中的變量
MariaDB [(none)]> SHOW VARIABLES LIKE 'datadir'; +---------------+--------------+ | Variable_name | Value | +---------------+--------------+ | datadir | /data/mysql/ | +---------------+--------------+ 1 row in set (0.00 sec) MariaDB [(none)]>
MariaDB [(none)]> SELECT @@datadir; +--------------+ | @@datadir | +--------------+ | /data/mysql/ | +--------------+ 1 row in set (0.00 sec) MariaDB [(none)]>
10>.查看系統支持的字符集(包含每一個字符集在磁盤上佔用字節大小)
MariaDB [(none)]> SHOW CHARACTER SET; +----------+-----------------------------+---------------------+--------+ | Charset | Description | Default collation | Maxlen | +----------+-----------------------------+---------------------+--------+ | big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 | | dec8 | DEC West European | dec8_swedish_ci | 1 | | cp850 | DOS West European | cp850_general_ci | 1 | | hp8 | HP West European | hp8_english_ci | 1 | | koi8r | KOI8-R Relcom Russian | koi8r_general_ci | 1 | | latin1 | cp1252 West European | latin1_swedish_ci | 1 | | latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 | | swe7 | 7bit Swedish | swe7_swedish_ci | 1 | | ascii | US ASCII | ascii_general_ci | 1 | | ujis | EUC-JP Japanese | ujis_japanese_ci | 3 | | sjis | Shift-JIS Japanese | sjis_japanese_ci | 2 | | hebrew | ISO 8859-8 Hebrew | hebrew_general_ci | 1 | | tis620 | TIS620 Thai | tis620_thai_ci | 1 | | euckr | EUC-KR Korean | euckr_korean_ci | 2 | | koi8u | KOI8-U Ukrainian | koi8u_general_ci | 1 | | gb2312 | GB2312 Simplified Chinese | gb2312_chinese_ci | 2 | | greek | ISO 8859-7 Greek | greek_general_ci | 1 | | cp1250 | Windows Central European | cp1250_general_ci | 1 | | gbk | GBK Simplified Chinese | gbk_chinese_ci | 2 | | latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 | | armscii8 | ARMSCII-8 Armenian | armscii8_general_ci | 1 | | utf8 | UTF-8 Unicode | utf8_general_ci | 3 | | ucs2 | UCS-2 Unicode | ucs2_general_ci | 2 | | cp866 | DOS Russian | cp866_general_ci | 1 | | keybcs2 | DOS Kamenicky Czech-Slovak | keybcs2_general_ci | 1 | | macce | Mac Central European | macce_general_ci | 1 | | macroman | Mac West European | macroman_general_ci | 1 | | cp852 | DOS Central European | cp852_general_ci | 1 | | latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 | | utf8mb4 | UTF-8 Unicode | utf8mb4_general_ci | 4 | | cp1251 | Windows Cyrillic | cp1251_general_ci | 1 | | utf16 | UTF-16 Unicode | utf16_general_ci | 4 | | utf16le | UTF-16LE Unicode | utf16le_general_ci | 4 | | cp1256 | Windows Arabic | cp1256_general_ci | 1 | | cp1257 | Windows Baltic | cp1257_general_ci | 1 | | utf32 | UTF-32 Unicode | utf32_general_ci | 4 | | binary | Binary pseudo charset | binary | 1 | | geostd8 | GEOSTD8 Georgian | geostd8_general_ci | 1 | | cp932 | SJIS for Windows Japanese | cp932_japanese_ci | 2 | | eucjpms | UJIS for Windows Japanese | eucjpms_japanese_ci | 3 | +----------+-----------------------------+---------------------+--------+ 40 rows in set (0.00 sec) MariaDB [(none)]
11>.查看默認的排序規則
MariaDB [(none)]> SHOW COLLATION; #查看字符集對應的默認排序規則 +------------------------------+----------+------+---------+----------+---------+ | Collation | Charset | Id | Default | Compiled | Sortlen | +------------------------------+----------+------+---------+----------+---------+ | big5_chinese_ci | big5 | 1 | Yes | Yes | 1 | | big5_bin | big5 | 84 | | Yes | 1 | | big5_chinese_nopad_ci | big5 | 1025 | | Yes | 1 | | big5_nopad_bin | big5 | 1108 | | Yes | 1 | | dec8_swedish_ci | dec8 | 3 | Yes | Yes | 1 | | dec8_bin | dec8 | 69 | | Yes | 1 | | dec8_swedish_nopad_ci | dec8 | 1027 | | Yes | 1 | | dec8_nopad_bin | dec8 | 1093 | | Yes | 1 | | cp850_general_ci | cp850 | 4 | Yes | Yes | 1 | | cp850_bin | cp850 | 80 | | Yes | 1 | | cp850_general_nopad_ci | cp850 | 1028 | | Yes | 1 | | cp850_nopad_bin | cp850 | 1104 | | Yes | 1 | | hp8_english_ci | hp8 | 6 | Yes | Yes | 1 | | hp8_bin | hp8 | 72 | | Yes | 1 | | hp8_english_nopad_ci | hp8 | 1030 | | Yes | 1 | | hp8_nopad_bin | hp8 | 1096 | | Yes | 1 | | koi8r_general_ci | koi8r | 7 | Yes | Yes | 1 | | koi8r_bin | koi8r | 74 | | Yes | 1 | | koi8r_general_nopad_ci | koi8r | 1031 | | Yes | 1 | | koi8r_nopad_bin | koi8r | 1098 | | Yes | 1 | | latin1_german1_ci | latin1 | 5 | | Yes | 1 | | latin1_swedish_ci | latin1 | 8 | Yes | Yes | 1 | | latin1_danish_ci | latin1 | 15 | | Yes | 1 | | latin1_german2_ci | latin1 | 31 | | Yes | 2 | | latin1_bin | latin1 | 47 | | Yes | 1 | | latin1_general_ci | latin1 | 48 | | Yes | 1 | | latin1_general_cs | latin1 | 49 | | Yes | 1 | | latin1_spanish_ci | latin1 | 94 | | Yes | 1 | | latin1_swedish_nopad_ci | latin1 | 1032 | | Yes | 1 | | latin1_nopad_bin | latin1 | 1071 | | Yes | 1 | | latin2_czech_cs | latin2 | 2 | | Yes | 4 | | latin2_general_ci | latin2 | 9 | Yes | Yes | 1 | | latin2_hungarian_ci | latin2 | 21 | | Yes | 1 | | latin2_croatian_ci | latin2 | 27 | | Yes | 1 | | latin2_bin | latin2 | 77 | | Yes | 1 | | latin2_general_nopad_ci | latin2 | 1033 | | Yes | 1 | | latin2_nopad_bin | latin2 | 1101 | | Yes | 1 | | swe7_swedish_ci | swe7 | 10 | Yes | Yes | 1 | | swe7_bin | swe7 | 82 | | Yes | 1 | | swe7_swedish_nopad_ci | swe7 | 1034 | | Yes | 1 | | swe7_nopad_bin | swe7 | 1106 | | Yes | 1 | | ascii_general_ci | ascii | 11 | Yes | Yes | 1 | | ascii_bin | ascii | 65 | | Yes | 1 | | ascii_general_nopad_ci | ascii | 1035 | | Yes | 1 | | ascii_nopad_bin | ascii | 1089 | | Yes | 1 | | ujis_japanese_ci | ujis | 12 | Yes | Yes | 1 | | ujis_bin | ujis | 91 | | Yes | 1 | | ujis_japanese_nopad_ci | ujis | 1036 | | Yes | 1 | | ujis_nopad_bin | ujis | 1115 | | Yes | 1 | | sjis_japanese_ci | sjis | 13 | Yes | Yes | 1 | | sjis_bin | sjis | 88 | | Yes | 1 | | sjis_japanese_nopad_ci | sjis | 1037 | | Yes | 1 | | sjis_nopad_bin | sjis | 1112 | | Yes | 1 | | hebrew_general_ci | hebrew | 16 | Yes | Yes | 1 | | hebrew_bin | hebrew | 71 | | Yes | 1 | | hebrew_general_nopad_ci | hebrew | 1040 | | Yes | 1 | | hebrew_nopad_bin | hebrew | 1095 | | Yes | 1 | | tis620_thai_ci | tis620 | 18 | Yes | Yes | 4 | | tis620_bin | tis620 | 89 | | Yes | 1 | | tis620_thai_nopad_ci | tis620 | 1042 | | Yes | 4 | | tis620_nopad_bin | tis620 | 1113 | | Yes | 1 | | euckr_korean_ci | euckr | 19 | Yes | Yes | 1 | | euckr_bin | euckr | 85 | | Yes | 1 | | euckr_korean_nopad_ci | euckr | 1043 | | Yes | 1 | | euckr_nopad_bin | euckr | 1109 | | Yes | 1 | | koi8u_general_ci | koi8u | 22 | Yes | Yes | 1 | | koi8u_bin | koi8u | 75 | | Yes | 1 | | koi8u_general_nopad_ci | koi8u | 1046 | | Yes | 1 | | koi8u_nopad_bin | koi8u | 1099 | | Yes | 1 | | gb2312_chinese_ci | gb2312 | 24 | Yes | Yes | 1 | | gb2312_bin | gb2312 | 86 | | Yes | 1 | | gb2312_chinese_nopad_ci | gb2312 | 1048 | | Yes | 1 | | gb2312_nopad_bin | gb2312 | 1110 | | Yes | 1 | | greek_general_ci | greek | 25 | Yes | Yes | 1 | | greek_bin | greek | 70 | | Yes | 1 | | greek_general_nopad_ci | greek | 1049 | | Yes | 1 | | greek_nopad_bin | greek | 1094 | | Yes | 1 | | cp1250_general_ci | cp1250 | 26 | Yes | Yes | 1 | | cp1250_czech_cs | cp1250 | 34 | | Yes | 2 | | cp1250_croatian_ci | cp1250 | 44 | | Yes | 1 | | cp1250_bin | cp1250 | 66 | | Yes | 1 | | cp1250_polish_ci | cp1250 | 99 | | Yes | 1 | | cp1250_general_nopad_ci | cp1250 | 1050 | | Yes | 1 | | cp1250_nopad_bin | cp1250 | 1090 | | Yes | 1 | | gbk_chinese_ci | gbk | 28 | Yes | Yes | 1 | | gbk_bin | gbk | 87 | | Yes | 1 | | gbk_chinese_nopad_ci | gbk | 1052 | | Yes | 1 | | gbk_nopad_bin | gbk | 1111 | | Yes | 1 | | latin5_turkish_ci | latin5 | 30 | Yes | Yes | 1 | | latin5_bin | latin5 | 78 | | Yes | 1 | | latin5_turkish_nopad_ci | latin5 | 1054 | | Yes | 1 | | latin5_nopad_bin | latin5 | 1102 | | Yes | 1 | | armscii8_general_ci | armscii8 | 32 | Yes | Yes | 1 | | armscii8_bin | armscii8 | 64 | | Yes | 1 | | armscii8_general_nopad_ci | armscii8 | 1056 | | Yes | 1 | | armscii8_nopad_bin | armscii8 | 1088 | | Yes | 1 | | utf8_general_ci | utf8 | 33 | Yes | Yes | 1 | | utf8_bin | utf8 | 83 | | Yes | 1 | | utf8_unicode_ci | utf8 | 192 | | Yes | 8 | | utf8_icelandic_ci | utf8 | 193 | | Yes | 8 | | utf8_latvian_ci | utf8 | 194 | | Yes | 8 | | utf8_romanian_ci | utf8 | 195 | | Yes | 8 | | utf8_slovenian_ci | utf8 | 196 | | Yes | 8 | | utf8_polish_ci | utf8 | 197 | | Yes | 8 | | utf8_estonian_ci | utf8 | 198 | | Yes | 8 | | utf8_spanish_ci | utf8 | 199 | | Yes | 8 | | utf8_swedish_ci | utf8 | 200 | | Yes | 8 | | utf8_turkish_ci | utf8 | 201 | | Yes | 8 | | utf8_czech_ci | utf8 | 202 | | Yes | 8 | | utf8_danish_ci | utf8 | 203 | | Yes | 8 | | utf8_lithuanian_ci | utf8 | 204 | | Yes | 8 | | utf8_slovak_ci | utf8 | 205 | | Yes | 8 | | utf8_spanish2_ci | utf8 | 206 | | Yes | 8 | | utf8_roman_ci | utf8 | 207 | | Yes | 8 | | utf8_persian_ci | utf8 | 208 | | Yes | 8 | | utf8_esperanto_ci | utf8 | 209 | | Yes | 8 | | utf8_hungarian_ci | utf8 | 210 | | Yes | 8 | | utf8_sinhala_ci | utf8 | 211 | | Yes | 8 | | utf8_german2_ci | utf8 | 212 | | Yes | 8 | | utf8_croatian_mysql561_ci | utf8 | 213 | | Yes | 8 | | utf8_unicode_520_ci | utf8 | 214 | | Yes | 8 | | utf8_vietnamese_ci | utf8 | 215 | | Yes | 8 | | utf8_general_mysql500_ci | utf8 | 223 | | Yes | 1 | | utf8_croatian_ci | utf8 | 576 | | Yes | 8 | | utf8_myanmar_ci | utf8 | 577 | | Yes | 8 | | utf8_thai_520_w2 | utf8 | 578 | | Yes | 4 | | utf8_general_nopad_ci | utf8 | 1057 | | Yes | 1 | | utf8_nopad_bin | utf8 | 1107 | | Yes | 1 | | utf8_unicode_nopad_ci | utf8 | 1216 | | Yes | 8 | | utf8_unicode_520_nopad_ci | utf8 | 1238 | | Yes | 8 | | ucs2_general_ci | ucs2 | 35 | Yes | Yes | 1 | | ucs2_bin | ucs2 | 90 | | Yes | 1 | | ucs2_unicode_ci | ucs2 | 128 | | Yes | 8 | | ucs2_icelandic_ci | ucs2 | 129 | | Yes | 8 | | ucs2_latvian_ci | ucs2 | 130 | | Yes | 8 | | ucs2_romanian_ci | ucs2 | 131 | | Yes | 8 | | ucs2_slovenian_ci | ucs2 | 132 | | Yes | 8 | | ucs2_polish_ci | ucs2 | 133 | | Yes | 8 | | ucs2_estonian_ci | ucs2 | 134 | | Yes | 8 | | ucs2_spanish_ci | ucs2 | 135 | | Yes | 8 | | ucs2_swedish_ci | ucs2 | 136 | | Yes | 8 | | ucs2_turkish_ci | ucs2 | 137 | | Yes | 8 | | ucs2_czech_ci | ucs2 | 138 | | Yes | 8 | | ucs2_danish_ci | ucs2 | 139 | | Yes | 8 | | ucs2_lithuanian_ci | ucs2 | 140 | | Yes | 8 | | ucs2_slovak_ci | ucs2 | 141 | | Yes | 8 | | ucs2_spanish2_ci | ucs2 | 142 | | Yes | 8 | | ucs2_roman_ci | ucs2 | 143 | | Yes | 8 | | ucs2_persian_ci | ucs2 | 144 | | Yes | 8 | | ucs2_esperanto_ci | ucs2 | 145 | | Yes | 8 | | ucs2_hungarian_ci | ucs2 | 146 | | Yes | 8 | | ucs2_sinhala_ci | ucs2 | 147 | | Yes | 8 | | ucs2_german2_ci | ucs2 | 148 | | Yes | 8 | | ucs2_croatian_mysql561_ci | ucs2 | 149 | | Yes | 8 | | ucs2_unicode_520_ci | ucs2 | 150 | | Yes | 8 | | ucs2_vietnamese_ci | ucs2 | 151 | | Yes | 8 | | ucs2_general_mysql500_ci | ucs2 | 159 | | Yes | 1 | | ucs2_croatian_ci | ucs2 | 640 | | Yes | 8 | | ucs2_myanmar_ci | ucs2 | 641 | | Yes | 8 | | ucs2_thai_520_w2 | ucs2 | 642 | | Yes | 4 | | ucs2_general_nopad_ci | ucs2 | 1059 | | Yes | 1 | | ucs2_nopad_bin | ucs2 | 1114 | | Yes | 1 | | ucs2_unicode_nopad_ci | ucs2 | 1152 | | Yes | 8 | | ucs2_unicode_520_nopad_ci | ucs2 | 1174 | | Yes | 8 | | cp866_general_ci | cp866 | 36 | Yes | Yes | 1 | | cp866_bin | cp866 | 68 | | Yes | 1 | | cp866_general_nopad_ci | cp866 | 1060 | | Yes | 1 | | cp866_nopad_bin | cp866 | 1092 | | Yes | 1 | | keybcs2_general_ci | keybcs2 | 37 | Yes | Yes | 1 | | keybcs2_bin | keybcs2 | 73 | | Yes | 1 | | keybcs2_general_nopad_ci | keybcs2 | 1061 | | Yes | 1 | | keybcs2_nopad_bin | keybcs2 | 1097 | | Yes | 1 | | macce_general_ci | macce | 38 | Yes | Yes | 1 | | macce_bin | macce | 43 | | Yes | 1 | | macce_general_nopad_ci | macce | 1062 | | Yes | 1 | | macce_nopad_bin | macce | 1067 | | Yes | 1 | | macroman_general_ci | macroman | 39 | Yes | Yes | 1 | | macroman_bin | macroman | 53 | | Yes | 1 | | macroman_general_nopad_ci | macroman | 1063 | | Yes | 1 | | macroman_nopad_bin | macroman | 1077 | | Yes | 1 | | cp852_general_ci | cp852 | 40 | Yes | Yes | 1 | | cp852_bin | cp852 | 81 | | Yes | 1 | | cp852_general_nopad_ci | cp852 | 1064 | | Yes | 1 | | cp852_nopad_bin | cp852 | 1105 | | Yes | 1 | | latin7_estonian_cs | latin7 | 20 | | Yes | 1 | | latin7_general_ci | latin7 | 41 | Yes | Yes | 1 | | latin7_general_cs | latin7 | 42 | | Yes | 1 | | latin7_bin | latin7 | 79 | | Yes | 1 | | latin7_general_nopad_ci | latin7 | 1065 | | Yes | 1 | | latin7_nopad_bin | latin7 | 1103 | | Yes | 1 | | utf8mb4_general_ci | utf8mb4 | 45 | Yes | Yes | 1 | | utf8mb4_bin | utf8mb4 | 46 | | Yes | 1 | | utf8mb4_unicode_ci | utf8mb4 | 224 | | Yes | 8 | | utf8mb4_icelandic_ci | utf8mb4 | 225 | | Yes | 8 | | utf8mb4_latvian_ci | utf8mb4 | 226 | | Yes | 8 | | utf8mb4_romanian_ci | utf8mb4 | 227 | | Yes | 8 | | utf8mb4_slovenian_ci | utf8mb4 | 228 | | Yes | 8 | | utf8mb4_polish_ci | utf8mb4 | 229 | | Yes | 8 | | utf8mb4_estonian_ci | utf8mb4 | 230 | | Yes | 8 | | utf8mb4_spanish_ci | utf8mb4 | 231 | | Yes | 8 | | utf8mb4_swedish_ci | utf8mb4 | 232 | | Yes | 8 | | utf8mb4_turkish_ci | utf8mb4 | 233 | | Yes | 8 | | utf8mb4_czech_ci | utf8mb4 | 234 | | Yes | 8 | | utf8mb4_danish_ci | utf8mb4 | 235 | | Yes | 8 | | utf8mb4_lithuanian_ci | utf8mb4 | 236 | | Yes | 8 | | utf8mb4_slovak_ci | utf8mb4 | 237 | | Yes | 8 | | utf8mb4_spanish2_ci | utf8mb4 | 238 | | Yes | 8 | | utf8mb4_roman_ci | utf8mb4 | 239 | | Yes | 8 | | utf8mb4_persian_ci | utf8mb4 | 240 | | Yes | 8 | | utf8mb4_esperanto_ci | utf8mb4 | 241 | | Yes | 8 | | utf8mb4_hungarian_ci | utf8mb4 | 242 | | Yes | 8 | | utf8mb4_sinhala_ci | utf8mb4 | 243 | | Yes | 8 | | utf8mb4_german2_ci | utf8mb4 | 244 | | Yes | 8 | | utf8mb4_croatian_mysql561_ci | utf8mb4 | 245 | | Yes | 8 | | utf8mb4_unicode_520_ci | utf8mb4 | 246 | | Yes | 8 | | utf8mb4_vietnamese_ci | utf8mb4 | 247 | | Yes | 8 | | utf8mb4_croatian_ci | utf8mb4 | 608 | | Yes | 8 | | utf8mb4_myanmar_ci | utf8mb4 | 609 | | Yes | 8 | | utf8mb4_thai_520_w2 | utf8mb4 | 610 | | Yes | 4 | | utf8mb4_general_nopad_ci | utf8mb4 | 1069 | | Yes | 1 | | utf8mb4_nopad_bin | utf8mb4 | 1070 | | Yes | 1 | | utf8mb4_unicode_nopad_ci | utf8mb4 | 1248 | | Yes | 8 | | utf8mb4_unicode_520_nopad_ci | utf8mb4 | 1270 | | Yes | 8 | | cp1251_bulgarian_ci | cp1251 | 14 | | Yes | 1 | | cp1251_ukrainian_ci | cp1251 | 23 | | Yes | 1 | | cp1251_bin | cp1251 | 50 | | Yes | 1 | | cp1251_general_ci | cp1251 | 51 | Yes | Yes | 1 | | cp1251_general_cs | cp1251 | 52 | | Yes | 1 | | cp1251_nopad_bin | cp1251 | 1074 | | Yes | 1 | | cp1251_general_nopad_ci | cp1251 | 1075 | | Yes | 1 | | utf16_general_ci | utf16 | 54 | Yes | Yes | 1 | | utf16_bin | utf16 | 55 | | Yes | 1 | | utf16_unicode_ci | utf16 | 101 | | Yes | 8 | | utf16_icelandic_ci | utf16 | 102 | | Yes | 8 | | utf16_latvian_ci | utf16 | 103 | | Yes | 8 | | utf16_romanian_ci | utf16 | 104 | | Yes | 8 | | utf16_slovenian_ci | utf16 | 105 | | Yes | 8 | | utf16_polish_ci | utf16 | 106 | | Yes | 8 | | utf16_estonian_ci | utf16 | 107 | | Yes | 8 | | utf16_spanish_ci | utf16 | 108 | | Yes | 8 | | utf16_swedish_ci | utf16 | 109 | | Yes | 8 | | utf16_turkish_ci | utf16 | 110 | | Yes | 8 | | utf16_czech_ci | utf16 | 111 | | Yes | 8 | | utf16_danish_ci | utf16 | 112 | | Yes | 8 | | utf16_lithuanian_ci | utf16 | 113 | | Yes | 8 | | utf16_slovak_ci | utf16 | 114 | | Yes | 8 | | utf16_spanish2_ci | utf16 | 115 | | Yes | 8 | | utf16_roman_ci | utf16 | 116 | | Yes | 8 | | utf16_persian_ci | utf16 | 117 | | Yes | 8 | | utf16_esperanto_ci | utf16 | 118 | | Yes | 8 | | utf16_hungarian_ci | utf16 | 119 | | Yes | 8 | | utf16_sinhala_ci | utf16 | 120 | | Yes | 8 | | utf16_german2_ci | utf16 | 121 | | Yes | 8 | | utf16_croatian_mysql561_ci | utf16 | 122 | | Yes | 8 | | utf16_unicode_520_ci | utf16 | 123 | | Yes | 8 | | utf16_vietnamese_ci | utf16 | 124 | | Yes | 8 | | utf16_croatian_ci | utf16 | 672 | | Yes | 8 | | utf16_myanmar_ci | utf16 | 673 | | Yes | 8 | | utf16_thai_520_w2 | utf16 | 674 | | Yes | 4 | | utf16_general_nopad_ci | utf16 | 1078 | | Yes | 1 | | utf16_nopad_bin | utf16 | 1079 | | Yes | 1 | | utf16_unicode_nopad_ci | utf16 | 1125 | | Yes | 8 | | utf16_unicode_520_nopad_ci | utf16 | 1147 | | Yes | 8 | | utf16le_general_ci | utf16le | 56 | Yes | Yes | 1 | | utf16le_bin | utf16le | 62 | | Yes | 1 | | utf16le_general_nopad_ci | utf16le | 1080 | | Yes | 1 | | utf16le_nopad_bin | utf16le | 1086 | | Yes | 1 | | cp1256_general_ci | cp1256 | 57 | Yes | Yes | 1 | | cp1256_bin | cp1256 | 67 | | Yes | 1 | | cp1256_general_nopad_ci | cp1256 | 1081 | | Yes | 1 | | cp1256_nopad_bin | cp1256 | 1091 | | Yes | 1 | | cp1257_lithuanian_ci | cp1257 | 29 | | Yes | 1 | | cp1257_bin | cp1257 | 58 | | Yes | 1 | | cp1257_general_ci | cp1257 | 59 | Yes | Yes | 1 | | cp1257_nopad_bin | cp1257 | 1082 | | Yes | 1 | | cp1257_general_nopad_ci | cp1257 | 1083 | | Yes | 1 | | utf32_general_ci | utf32 | 60 | Yes | Yes | 1 | | utf32_bin | utf32 | 61 | | Yes | 1 | | utf32_unicode_ci | utf32 | 160 | | Yes | 8 | | utf32_icelandic_ci | utf32 | 161 | | Yes | 8 | | utf32_latvian_ci | utf32 | 162 | | Yes | 8 | | utf32_romanian_ci | utf32 | 163 | | Yes | 8 | | utf32_slovenian_ci | utf32 | 164 | | Yes | 8 | | utf32_polish_ci | utf32 | 165 | | Yes | 8 | | utf32_estonian_ci | utf32 | 166 | | Yes | 8 | | utf32_spanish_ci | utf32 | 167 | | Yes | 8 | | utf32_swedish_ci | utf32 | 168 | | Yes | 8 | | utf32_turkish_ci | utf32 | 169 | | Yes | 8 | | utf32_czech_ci | utf32 | 170 | | Yes | 8 | | utf32_danish_ci | utf32 | 171 | | Yes | 8 | | utf32_lithuanian_ci | utf32 | 172 | | Yes | 8 | | utf32_slovak_ci | utf32 | 173 | | Yes | 8 | | utf32_spanish2_ci | utf32 | 174 | | Yes | 8 | | utf32_roman_ci | utf32 | 175 | | Yes | 8 | | utf32_persian_ci | utf32 | 176 | | Yes | 8 | | utf32_esperanto_ci | utf32 | 177 | | Yes | 8 | | utf32_hungarian_ci | utf32 | 178 | | Yes | 8 | | utf32_sinhala_ci | utf32 | 179 | | Yes | 8 | | utf32_german2_ci | utf32 | 180 | | Yes | 8 | | utf32_croatian_mysql561_ci | utf32 | 181 | | Yes | 8 | | utf32_unicode_520_ci | utf32 | 182 | | Yes | 8 | | utf32_vietnamese_ci | utf32 | 183 | | Yes | 8 | | utf32_croatian_ci | utf32 | 736 | | Yes | 8 | | utf32_myanmar_ci | utf32 | 737 | | Yes | 8 | | utf32_thai_520_w2 | utf32 | 738 | | Yes | 4 | | utf32_general_nopad_ci | utf32 | 1084 | | Yes | 1 | | utf32_nopad_bin | utf32 | 1085 | | Yes | 1 | | utf32_unicode_nopad_ci | utf32 | 1184 | | Yes | 8 | | utf32_unicode_520_nopad_ci | utf32 | 1206 | | Yes | 8 | | binary | binary | 63 | Yes | Yes | 1 | | geostd8_general_ci | geostd8 | 92 | Yes | Yes | 1 | | geostd8_bin | geostd8 | 93 | | Yes | 1 | | geostd8_general_nopad_ci | geostd8 | 1116 | | Yes | 1 | | geostd8_nopad_bin | geostd8 | 1117 | | Yes | 1 | | cp932_japanese_ci | cp932 | 95 | Yes | Yes | 1 | | cp932_bin | cp932 | 96 | | Yes | 1 | | cp932_japanese_nopad_ci | cp932 | 1119 | | Yes | 1 | | cp932_nopad_bin | cp932 | 1120 | | Yes | 1 | | eucjpms_japanese_ci | eucjpms | 97 | Yes | Yes | 1 | | eucjpms_bin | eucjpms | 98 | | Yes | 1 | | eucjpms_japanese_nopad_ci | eucjpms | 1121 | | Yes | 1 | | eucjpms_nopad_bin | eucjpms | 1122 | | Yes | 1 | +------------------------------+----------+------+---------+----------+---------+ 322 rows in set (0.00 sec) MariaDB [(none)]>
12>.查看數據庫當前使用的字符集
MariaDB [(none)]> SHOW CREATE DATABASE yinzhengjie; +-------------+------------------------------------------------------------------------+ | Database | Create Database | +-------------+------------------------------------------------------------------------+ | yinzhengjie | CREATE DATABASE `yinzhengjie` /*!40100 DEFAULT CHARACTER SET latin1 */ | +-------------+------------------------------------------------------------------------+ 1 row in set (0.00 sec) MariaDB [(none)]>
MariaDB [(none)]> SHOW CREATE DATABASE yinzhengjie2019; +-----------------+-----------------------------------------------------------------------------+ | Database | Create Database | +-----------------+-----------------------------------------------------------------------------+ | yinzhengjie2019 | CREATE DATABASE `yinzhengjie2019` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ | +-----------------+-----------------------------------------------------------------------------+ 1 row in set (0.00 sec) MariaDB [(none)]>
13>.查看錶建立命令
MariaDB [yinzhengjie]> SHOW CREATE TABLE students; +----------+------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table |+----------+------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+| students | CREATE TABLE `students` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(30) NOT NULL, `sex` enum('boy','girl') DEFAULT 'boy', `age` tinyint(3) unsigned DEFAULT NULL, `mobile` char(11) DEFAULT NULL, `address` varchar(50) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 | +----------+------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+1 row in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SHOW CREATE TABLE students\G *************************** 1. row *************************** Table: students Create Table: CREATE TABLE `students` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(30) NOT NULL, `sex` enum('boy','girl') DEFAULT 'boy', `age` tinyint(3) unsigned DEFAULT NULL, `mobile` char(11) DEFAULT NULL, `address` varchar(50) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
14>.查看錶狀態
MariaDB [yinzhengjie]> SHOW TABLE STATUS LIKE 'students'; +----------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+- --------------------+-------------+------------+-------------------+----------+----------------+---------+| Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment |+----------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+- --------------------+-------------+------------+-------------------+----------+----------------+---------+| students | InnoDB | 10 | Dynamic | 0 | 0 | 16384 | 0 | 0 | 0 | 1 | 2019-10-27 09:23:27 | NULL | NULL | latin1_swedish_ci | NULL | | |+----------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+- --------------------+-------------+------------+-------------------+----------+----------------+---------+1 row in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SHOW TABLE STATUS LIKE 'students'\G *************************** 1. row *************************** Name: students Engine: InnoDB Version: 10 Row_format: Dynamic Rows: 0 Avg_row_length: 0 Data_length: 16384 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: 1 Create_time: 2019-10-27 09:23:27 Update_time: NULL Check_time: NULL Collation: latin1_swedish_ci Checksum: NULL Create_options: Comment: 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SHOW TABLE STATUS FROM mysql; #若是指定的是庫名的話就不須要給"mysql"加單引號啦~ +---------------------------+--------+---------+------------+------+----------------+-------------+--------------------+--------------+---------- -+----------------+---------------------+---------------------+---------------------+-------------------+----------+--------------------+---------------------------------------------------+| Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment |+---------------------------+--------+---------+------------+------+----------------+-------------+--------------------+--------------+---------- -+----------------+---------------------+---------------------+---------------------+-------------------+----------+--------------------+---------------------------------------------------+| column_stats | MyISAM | 10 | Dynamic | 0 | 0 | 0 | 281474976710655 | 4096 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | Statistics on Columns || columns_priv | MyISAM | 10 | Fixed | 0 | 0 | 0 | 282037926664077311 | 4096 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | Column privileges || db | MyISAM | 10 | Fixed | 0 | 0 | 1264 | 177892185281134591 | 9216 | 1264 | NULL | 2019-10-26 22:17:15 | 2019-10-26 23:43:41 | 2019-10-26 22:17:15 | utf8_bin | NULL | | Database privileges || event | MyISAM | 10 | Dynamic | 0 | 0 | 0 | 281474976710655 | 2048 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | Events || func | MyISAM | 10 | Fixed | 0 | 0 | 0 | 162974011515469823 | 1024 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | User defined functions || general_log | CSV | 10 | Dynamic | 2 | 0 | 0 | 0 | 0 | 0 | NULL | NULL | NULL | NULL | utf8_general_ci | NULL | | General log || gtid_slave_pos | InnoDB | 10 | Dynamic | 0 | 0 | 16384 | 0 | 0 | 0 | NULL | 2019-10-26 23:25:39 | NULL | NULL | latin1_swedish_ci | NULL | | Replication slave GTID position || help_category | MyISAM | 10 | Dynamic | 39 | 28 | 1092 | 281474976710655 | 3072 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | help categories || help_keyword | MyISAM | 10 | Fixed | 464 | 197 | 91408 | 55450570411999231 | 16384 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | help keywords || help_relation | MyISAM | 10 | Fixed | 1028 | 9 | 9252 | 2533274790395903 | 19456 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | keyword-topic relation || help_topic | MyISAM | 10 | Dynamic | 508 | 798 | 405476 | 281474976710655 | 20480 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | help topics || host | MyISAM | 10 | Fixed | 0 | 0 | 0 | 110056715893866495 | 2048 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | Host privileges; Merged with database privileges || index_stats | MyISAM | 10 | Dynamic | 0 | 0 | 0 | 281474976710655 | 4096 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | Statistics on Indexes || innodb_index_stats | InnoDB | 10 | Dynamic | 7 | 2340 | 16384 | 0 | 0 | 0 | NULL | 2019-10-26 23:25:39 | 2019-10-27 09:23:27 | NULL | utf8_bin | NULL | stats_persistent=0 | || innodb_table_stats | InnoDB | 10 | Dynamic | 2 | 8192 | 16384 | 0 | 0 | 0 | NULL | 2019-10-26 23:25:39 | 2019-10-27 09:23:27 | NULL | utf8_bin | NULL | stats_persistent=0 | || plugin | MyISAM | 10 | Dynamic | 0 | 0 | 0 | 281474976710655 | 1024 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | MySQL plugins || proc | MyISAM | 10 | Dynamic | 2 | 564 | 1128 | 281474976710655 | 4096 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | Stored Procedures || procs_priv | MyISAM | 10 | Fixed | 0 | 0 | 0 | 347340121260949503 | 4096 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | Procedure privileges || proxies_priv | MyISAM | 10 | Fixed | 2 | 1269 | 2538 | 357191745445822463 | 10240 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | utf8_bin | NULL | | User proxy privileges || roles_mapping | MyISAM | 10 | Fixed | 0 | 0 | 0 | 186336434582454271 | 4096 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | Granted roles || servers | MyISAM | 10 | Fixed | 0 | 0 | 0 | 447263737993232383 | 1024 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | MySQL Foreign Servers table || slow_log | CSV | 10 | Dynamic | 2 | 0 | 0 | 0 | 0 | 0 | NULL | NULL | NULL | NULL | utf8_general_ci | NULL | | Slow log || table_stats | MyISAM | 10 | Dynamic | 0 | 0 | 0 | 281474976710655 | 2048 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | Statistics on Tables || tables_priv | MyISAM | 10 | Fixed | 0 | 0 | 0 | 347621596237660159 | 4096 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_bin | NULL | | Table privileges || time_zone | MyISAM | 10 | Fixed | 0 | 0 | 0 | 1970324836974591 | 1024 | 0 | 1 | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | Time zones || time_zone_leap_second | MyISAM | 10 | Fixed | 0 | 0 | 0 | 3659174697238527 | 1024 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | Leap seconds information for time zones || time_zone_name | MyISAM | 10 | Fixed | 0 | 0 | 0 | 55450570411999231 | 1024 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | Time zone names || time_zone_transition | MyISAM | 10 | Fixed | 0 | 0 | 0 | 4785074604081151 | 1024 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | Time zone transitions || time_zone_transition_type | MyISAM | 10 | Fixed | 0 | 0 | 0 | 10696049115004927 | 1024 | 0 | NULL | 2019-10-26 22:17:15 | 2019-10-26 22:17:15 | NULL | utf8_general_ci | NULL | | Time zone transition types || user | MyISAM | 10 | Dynamic | 3 | 113 | 608 | 281474976710655 | 4096 | 268 | NULL | 2019-10-26 22:17:15 | 2019-10-26 23:43:38 | NULL | utf8_bin | NULL | | Users and global privileges |+---------------------------+--------+---------+------------+------+----------------+-------------+--------------------+--------------+---------- -+----------------+---------------------+---------------------+---------------------+-------------------+----------+--------------------+---------------------------------------------------+30 rows in set (0.01 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SHOW TABLE STATUS FROM mysql\G *************************** 1. row *************************** Name: column_stats Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 281474976710655 Index_length: 4096 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Statistics on Columns *************************** 2. row *************************** Name: columns_priv Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 282037926664077311 Index_length: 4096 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Column privileges *************************** 3. row *************************** Name: db Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 1264 Max_data_length: 177892185281134591 Index_length: 9216 Data_free: 1264 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 23:43:41 Check_time: 2019-10-26 22:17:15 Collation: utf8_bin Checksum: NULL Create_options: Comment: Database privileges *************************** 4. row *************************** Name: event Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 281474976710655 Index_length: 2048 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: Events *************************** 5. row *************************** Name: func Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 162974011515469823 Index_length: 1024 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: User defined functions *************************** 6. row *************************** Name: general_log Engine: CSV Version: 10 Row_format: Dynamic Rows: 2 Avg_row_length: 0 Data_length: 0 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time: NULL Update_time: NULL Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: General log *************************** 7. row *************************** Name: gtid_slave_pos Engine: InnoDB Version: 10 Row_format: Dynamic Rows: 0 Avg_row_length: 0 Data_length: 16384 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 23:25:39 Update_time: NULL Check_time: NULL Collation: latin1_swedish_ci Checksum: NULL Create_options: Comment: Replication slave GTID position *************************** 8. row *************************** Name: help_category Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 39 Avg_row_length: 28 Data_length: 1092 Max_data_length: 281474976710655 Index_length: 3072 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: help categories *************************** 9. row *************************** Name: help_keyword Engine: MyISAM Version: 10 Row_format: Fixed Rows: 464 Avg_row_length: 197 Data_length: 91408 Max_data_length: 55450570411999231 Index_length: 16384 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: help keywords *************************** 10. row *************************** Name: help_relation Engine: MyISAM Version: 10 Row_format: Fixed Rows: 1028 Avg_row_length: 9 Data_length: 9252 Max_data_length: 2533274790395903 Index_length: 19456 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: keyword-topic relation *************************** 11. row *************************** Name: help_topic Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 508 Avg_row_length: 798 Data_length: 405476 Max_data_length: 281474976710655 Index_length: 20480 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: help topics *************************** 12. row *************************** Name: host Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 110056715893866495 Index_length: 2048 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Host privileges; Merged with database privileges *************************** 13. row *************************** Name: index_stats Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 281474976710655 Index_length: 4096 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Statistics on Indexes *************************** 14. row *************************** Name: innodb_index_stats Engine: InnoDB Version: 10 Row_format: Dynamic Rows: 7 Avg_row_length: 2340 Data_length: 16384 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 23:25:39 Update_time: 2019-10-27 09:23:27 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: stats_persistent=0 Comment: *************************** 15. row *************************** Name: innodb_table_stats Engine: InnoDB Version: 10 Row_format: Dynamic Rows: 2 Avg_row_length: 8192 Data_length: 16384 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 23:25:39 Update_time: 2019-10-27 09:23:27 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: stats_persistent=0 Comment: *************************** 16. row *************************** Name: plugin Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 281474976710655 Index_length: 1024 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: MySQL plugins *************************** 17. row *************************** Name: proc Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 2 Avg_row_length: 564 Data_length: 1128 Max_data_length: 281474976710655 Index_length: 4096 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: Stored Procedures *************************** 18. row *************************** Name: procs_priv Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 347340121260949503 Index_length: 4096 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Procedure privileges *************************** 19. row *************************** Name: proxies_priv Engine: MyISAM Version: 10 Row_format: Fixed Rows: 2 Avg_row_length: 1269 Data_length: 2538 Max_data_length: 357191745445822463 Index_length: 10240 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: 2019-10-26 22:17:15 Collation: utf8_bin Checksum: NULL Create_options: Comment: User proxy privileges *************************** 20. row *************************** Name: roles_mapping Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 186336434582454271 Index_length: 4096 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Granted roles *************************** 21. row *************************** Name: servers Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 447263737993232383 Index_length: 1024 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: MySQL Foreign Servers table *************************** 22. row *************************** Name: slow_log Engine: CSV Version: 10 Row_format: Dynamic Rows: 2 Avg_row_length: 0 Data_length: 0 Max_data_length: 0 Index_length: 0 Data_free: 0 Auto_increment: NULL Create_time: NULL Update_time: NULL Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: Slow log *************************** 23. row *************************** Name: table_stats Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 281474976710655 Index_length: 2048 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Statistics on Tables *************************** 24. row *************************** Name: tables_priv Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 347621596237660159 Index_length: 4096 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Table privileges *************************** 25. row *************************** Name: time_zone Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 1970324836974591 Index_length: 1024 Data_free: 0 Auto_increment: 1 Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: Time zones *************************** 26. row *************************** Name: time_zone_leap_second Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 3659174697238527 Index_length: 1024 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: Leap seconds information for time zones *************************** 27. row *************************** Name: time_zone_name Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 55450570411999231 Index_length: 1024 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: Time zone names *************************** 28. row *************************** Name: time_zone_transition Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 4785074604081151 Index_length: 1024 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: Time zone transitions *************************** 29. row *************************** Name: time_zone_transition_type Engine: MyISAM Version: 10 Row_format: Fixed Rows: 0 Avg_row_length: 0 Data_length: 0 Max_data_length: 10696049115004927 Index_length: 1024 Data_free: 0 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 22:17:15 Check_time: NULL Collation: utf8_general_ci Checksum: NULL Create_options: Comment: Time zone transition types *************************** 30. row *************************** Name: user Engine: MyISAM Version: 10 Row_format: Dynamic Rows: 3 Avg_row_length: 113 Data_length: 608 Max_data_length: 281474976710655 Index_length: 4096 Data_free: 268 Auto_increment: NULL Create_time: 2019-10-26 22:17:15 Update_time: 2019-10-26 23:43:38 Check_time: NULL Collation: utf8_bin Checksum: NULL Create_options: Comment: Users and global privileges 30 rows in set (0.00 sec) MariaDB [yinzhengjie]>
15>.查看錶上的索引
MariaDB [yinzhengjie]> SHOW INDEXES FROM students; +----------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---- -----------+| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Ind ex_comment |+----------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---- -----------+| students | 0 | PRIMARY | 1 | id | A | 0 | NULL | NULL | | BTREE | | |+----------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---- -----------+1 row in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SHOW INDEXES FROM students\G *************************** 1. row *************************** Table: students Non_unique: 0 Key_name: PRIMARY Seq_in_index: 1 Column_name: id Collation: A Cardinality: 0 Sub_part: NULL Packed: NULL Null: Index_type: BTREE Comment: Index_comment: 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
16>.查看一張表中有多少行數據
MariaDB [yinzhengjie]> SELECT COUNT(*) FROM students; +----------+ | COUNT(*) | +----------+ | 2 | +----------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
17>.查看錶中個別字段併爲其設置別名顯示
MariaDB [yinzhengjie]> SELECT * FROM students; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | adress | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT name AS 姓名 ,age 年齡, adress AS 地址 FROM students; +-----------+--------+---------+ | 姓名 | 年齡 | 地址 | +-----------+--------+---------+ | Jason Yin | 27 | beijing | | Jay | 40 | Taiwan | +-----------+--------+---------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
18>.對查詢的某列數據去重
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT DISTINCT sex FROM students; +------+ | sex | +------+ | boy | | girl | +------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
19>.LIKE語句
%: 任意長度的任意字符 _: 任意單個字符
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE name LIKE 'J%'; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | adress | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE name LIKE '%a%'; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE name LIKE '_ay'; +----+------+------+------+--------+--------+ | id | name | sex | age | mobile | adress | +----+------+------+------+--------+--------+ | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+------+------+------+--------+--------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
20>.RLIKE語句
RLIKE：
正則表達式，索引失效，不建議使用
REGEXP：
匹配字符串可用正則表達式書寫模式，同上
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE name RLIKE '^J'; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | adress | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+-----------+------+------+--------+---------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
21>.WHERE子句
指明過濾條件(布爾表達式)以實現「選擇」的功能： 算術操做符： 01.+ 02.- 03.* 04./ 05.% 比較操做符： 01.= 02.<=>（相等或都爲空） 03.<> 04.!=(非標準SQL) 05.> 06.>= 07.< 08.<= 09.BETWEEN min_num AND max_num 10.IN (element1, element2, ...) 11.IS NULL 12.IS NOT NULL
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE sex != 'boy'; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 3 rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE sex <> 'boy'; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 3 rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE mobile is null; +----+-----------+------+------+--------+--------+ | id | name | sex | age | mobile | adress | +----+-----------+------+------+--------+--------+ | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+-----------+------+------+--------+--------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE mobile is not null; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE age = 28 or age = 38; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE age IN (28,38); +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE age >= 25 and age <= 28; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE age BETWEEN 25 AND 28; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT 10*30; +-------+ | 10*30 | +-------+ | 300 | +-------+ row in set (0.00 sec) MariaDB [yinzhengjie]>
22>.邏輯操做符
01.NOT 02.AND 03.OR 04.XOR
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE NOT name RLIKE '^J'; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 4 rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE age = 28 OR age = 38; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE age = 28 XOR age = 38; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students WHERE age = 27 AND name = 'Jason Yin'; +----+-----------+------+------+--------+---------+ | id | name | sex | age | mobile | adress | +----+-----------+------+------+--------+---------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | +----+-----------+------+------+--------+---------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
23>.GROUP
根據指定的條件把查詢結果進行「分組」
以用於作「聚合」運算 avg(), max(), min(), count(), sum()
HAVING:
對分組聚合運算後的結果指定過濾條件
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 27 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT sex AS 性別,COUNT(*) AS 人數 FROM students GROUP BY sex; +--------+--------+ | 性別 | 人數 | +--------+--------+ | boy | 3 | | girl | 3 | +--------+--------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT sex AS 性別,AVG(age) AS 平均年齡 FROM students GROUP BY sex; +--------+--------------+ | 性別 | 平均年齡 | +--------+--------------+ | boy | 29.6667 | | girl | 32.6667 | +--------+--------------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT sex AS 性別,AVG(age) AS 平均年齡 FROM students GROUP BY sex HAVING sex = 'boy'; +--------+--------------+ | 性別 | 平均年齡 | +--------+--------------+ | boy | 29.6667 | +--------+--------------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT sex AS 性別,AVG(age) AS 平均年齡 FROM students WHERE sex = 'boy' GROUP BY sex; +--------+--------------+ | 性別 | 平均年齡 | +--------+--------------+ | boy | 29.6667 | +--------+--------------+ 1 row in set (0.00 sec) MariaDB [yinzhengjie]>
24>.ORDER BY
根據指定的字段對查詢結果進行排序 升序： ASC
降序： DESC
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students ORDER BY age ASC; #將排序的結果升序序顯示 +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students ORDER BY age; #默認就是將排序的結果升序顯示 +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | | 2 | Jay | boy | 40 | 10086 | Taiwan | +----+---------------------+------+------+---------+-----------+ rows in set (0.00 sec) MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students ORDER BY age DESC; #將排序的結果降序顯示 +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 2 | Jay | boy | 40 | 10086 | Taiwan | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 1 | Jason Yin | boy | 18 | 10000 | beijing | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
25>.LIMIT [[offset,]row_count]
對查詢的結果進行輸出行數數量限制
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students ORDER BY age DESC; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 2 | Jay | boy | 40 | 10086 | Taiwan | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 1 | Jason Yin | boy | 18 | 10000 | beijing | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students ORDER BY age DESC LIMIT 3; #查詢年齡最大的前3位 +----+-----------+------+------+--------+--------+ | id | name | sex | age | mobile | adress | +----+-----------+------+------+--------+--------+ | 2 | Jay | boy | 40 | 10086 | Taiwan | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | +----+-----------+------+------+--------+--------+ 3 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]>
MariaDB [yinzhengjie]> SELECT * FROM students; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 1 | Jason Yin | boy | 18 | 10000 | beijing | | 2 | Jay | boy | 40 | 10086 | Taiwan | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students ORDER BY age DESC; +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 2 | Jay | boy | 40 | 10086 | Taiwan | | 8 | 張娜拉 | girl | 38 | NULL | 首爾 | | 6 | 劉亦菲 | girl | 32 | NULL | 湖北 | | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | | 1 | Jason Yin | boy | 18 | 10000 | beijing | +----+---------------------+------+------+---------+-----------+ 6 rows in set (0.00 sec) MariaDB [yinzhengjie]> MariaDB [yinzhengjie]> SELECT * FROM students ORDER BY age DESC LIMIT 3,2; #跳過顯示年齡最大的前三個，從第三個開始顯示共計顯示2個 +----+---------------------+------+------+---------+-----------+ | id | name | sex | age | mobile | adress | +----+---------------------+------+------+---------+-----------+ | 7 | 汪蘇瀧 | boy | 31 | 5201314 | 遼寧 | | 5 | Gloria Tang Tsz-Kei | girl | 28 | 7474741 | Hong Kong | +----+---------------------+------+------+---------+-----------+ 2 rows in set (0.00 sec) MariaDB [yinzhengjie]>
26>.對查詢結果中的數據請求施加「鎖」
FOR UPDATE: 寫鎖，獨佔或排它鎖，只有一個讀和寫 LOCK IN SHARE MODE: 讀鎖，共享鎖，同時多個讀
27>.查看數據庫現有進程
MariaDB [yinzhengjie]> SHOW PROCESSLIST\G *************************** 1. row *************************** Id: 1 User: system user Host: db: NULL Command: Daemon Time: NULL State: InnoDB purge worker Info: NULL Progress: 0.000 *************************** 2. row *************************** Id: 2 User: system user Host: db: NULL Command: Daemon Time: NULL State: InnoDB purge coordinator Info: NULL Progress: 0.000 *************************** 3. row *************************** Id: 3 User: system user Host: db: NULL Command: Daemon Time: NULL State: InnoDB purge worker Info: NULL Progress: 0.000 *************************** 4. row *************************** Id: 4 User: system user Host: db: NULL Command: Daemon Time: NULL State: InnoDB purge worker Info: NULL Progress: 0.000 *************************** 5. row *************************** Id: 5 User: system user Host: db: NULL Command: Daemon Time: NULL State: InnoDB shutdown handler Info: NULL Progress: 0.000 *************************** 6. row *************************** Id: 10 User: root Host: localhost db: yinzhengjie Command: Query Time: 0 State: init Info: SHOW PROCESSLIST Progress: 0.000 6 rows in set (0.00 sec) MariaDB [yinzhengjie]>
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