重拾SQL——從無到有

2016.10.22

由於工做須要，在這裏提早重拾sql。

0.建立並選擇數據庫

mysql> SHOW DATABASES;

+--------------------+
| Database           |
+--------------------+
| information_schema |
| menagerie          |
| mysql              |
| performance_schema |
| phpmyadmin         |
| test               |
+--------------------+
6 rows in set (0.00 sec)

1.建立並選擇數據庫

mysql> CREATE DATABASE tianyuan;

Query OK, 1 row affected (0.00 sec)

2.查看建立後的數據庫

mysql> SHOW DATABASES;

+--------------------+
| Database           |
+--------------------+
| information_schema |
| menagerie          |
| mysql              |
| performance_schema |
| phpmyadmin         |
| test               |
| tianyuan           |
+--------------------+
7 rows in set (0.00 sec)

3.訪問它

mysql> USE tianyuan

Database changed

4.指定數據庫中表的佈局

mysql> CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20),
    -> species VARCHAR(20), sex CHAR(1), birth DATE, death DATE);

Query OK, 0 rows affected (0.14 sec)

5.顯示錶格

mysql> SHOW TABLES;

+--------------------+
| Tables_in_tianyuan |
+--------------------+
| pet                |
+--------------------+
1 row in set (0.00 sec)

6.驗證表是定期望的方式建立（若是你忘記表中的列的名稱或類型時）

mysql> DESCRIBE pet;

+---------+-------------+------+-----+---------+-------+
| Field   | Type        | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+-------+
| name    | varchar(20) | YES  |     | NULL    |       |
| owner   | varchar(20) | YES  |     | NULL    |       |
| species | varchar(20) | YES  |     | NULL    |       |
| sex     | char(1)     | YES  |     | NULL    |       |
| birth   | date        | YES  |     | NULL    |       |
| death   | date        | YES  |     | NULL    |       |
+---------+-------------+------+-----+---------+-------+
6 rows in set (0.01 sec)

7.選擇表格全部列的內容（無內容時）

mysql> SELECT * FROM pet;

Empty set (0.00 sec)

8.將數據裝入表中

• LOAD DATA

  mysql> LOAD DATA LOCAL INFILE '/Users/v/Desktop/1.txt' INTO TABLE pet;

  '/Users/v/Desktop/1.txt':
  

  
  
  Fluffy Harold cat f 1993-02-04
  
  Claws Gwen cat m 1994-03-17
  
  Buffy Harold dog f 1989-05-13
  
  

  ### 加載後

  
  
  Query OK, 3 rows affected, 3 warnings (0.07 sec)
  
  Records: 3 Deleted: 0 Skipped: 0 Warnings: 3
  
  

  ### 查看

  mysql> SELECT * FROM pet;

  
  
  +--------+--------+---------+------+------------+-------+
  
  | name | owner | species | sex | birth | death |
  
  +--------+--------+---------+------+------------+-------+
  
  | Fluffy | Harold | cat | f | 1993-02-04 | NULL |
  
  | Claws | Gwen | cat | m | 1994-03-17 | NULL |
  
  | Buffy | Harold | dog | f | 1989-05-13 | NULL |
  
  +--------+--------+---------+------+------------+-------+
  
  3 rows in set (0.00 sec)
  
  

• INSERT

  mysql> INSERT INTO pet 
      -> VALUES ('Puffball','Diane','hamster','f','1999-03-30',NULL);

  
  
  Query OK, 1 row affected (0.05 sec)
  
  

  ### 查看

  mysql> SELECT * FROM pet;

  
  
  +----------+--------+---------+------+------------+-------+
  
  | name | owner | species | sex | birth | death |
  
  +----------+--------+---------+------+------------+-------+
  
  | Fluffy | Harold | cat | f | 1993-02-04 | NULL |
  
  | Claws | Gwen | cat | m | 1994-03-17 | NULL |
  
  | Buffy | Harold | dog | f | 1989-05-13 | NULL |
  
  | Puffball | Diane | hamster | f | 1999-03-30 | NULL |
  
  +----------+--------+---------+------+------------+-------+
  
  4 rows in set (0.00 sec)
  
  

9.刪除數據庫

mysql> SHOW DATABASES;

+--------------------+
| Database           |
+--------------------+
| information_schema |
| menagerie          |
| mysql              |
| performance_schema |
| phpmyadmin         |
| test               |
| tianyuan           |
+--------------------+
7 rows in set (0.00 sec)

刪除

mysql> DROP DATABASE test;

Query OK, 0 rows affected (0.02 sec)

查看刪除效果

mysql> SHOW DATABASES;

+--------------------+
| Database           |
+--------------------+
| information_schema |
| menagerie          |
| mysql              |
| performance_schema |
| phpmyadmin         |
| tianyuan           |
+--------------------+
6 rows in set (0.00 sec)