MySql視圖

時間 2019-12-19

標籤 mysql 視圖欄目 MySQL 简体版

原文原文鏈接

MySql視圖mysql

1、爲何使用視圖

在數據庫中關於數據的查詢有時候很是麻煩，例如錶鏈接、子查詢等，這種查詢會很是痛苦，由於邏輯比較複雜、編寫語句比較多。當這種查詢須要重複使用時，則不會每次都能編寫正確，從而下降了數據庫的實用性。sql

在具體操做表前，有時候要求只能操做部分字段，而不是所有字段。數據庫

爲了提升複雜sql語句的複用性和表操做的安全性，mysql數據庫管理系統提供視圖特性。所謂的視圖，本質上是一種虛擬表，其內容與真實的表類似，包含一系列帶有名稱的列和行數據。可是，視圖並不在數據庫中以存儲的數據值形式存在。行和列的數據來自自定義視圖的查詢所引用的基本表，而且在具體引用視圖時動態生成。安全

視圖主要關注某些特定數據和他們所查詢的數據內容，這樣只能看到視圖中所定義的數據，而不是視圖所引用表中的數據，從而提升了數據庫中數據的安全性。微信

視圖的特色以下：ide

l 視圖的列能夠來自不一樣的表，是表的抽象和在邏輯意義上創建的新關係函數

l 視圖是由基本表（實表）產生的表（虛表）微信支付

l 視圖的創建和刪除不影響基本表ui

l 對視圖內容的更新（添加、刪除和修改）直接影響基本表this

l 當視圖來自多個基本表時，不容許添加和刪除數據

2、建立視圖

視圖的操做包括建立視圖，查看視圖、刪除視圖和修改視圖。在建立視圖時，首先要確保擁有CREATE VIEW的權限，而且同時確保對建立視圖所引用的表也具備相應的權限。

2.1、建立視圖的語法形式

雖然視圖能夠被當作是一種虛擬表，可是在其物理上是不存在的，即數據庫管理系統沒有專門的位置爲視圖存儲數據。根據視圖的概念能夠發現其數據來源於查詢語句，所以建立視圖的語法爲：

CREATE VIEW VIEW_NAME AS 查詢語句

和建立表同樣，視圖名不能和表名、也不能和其餘的視圖名稱重名。根據上述語法能夠發現，視圖的功能實際上就是封裝了複雜的查詢語句。

注：在SQL語句命名規範中，視圖通常以view_XXX或者v_XXX的樣式來命名。例子以下：

【列子1】建立students表中年齡小於20的視圖名字爲s

MySQL [yuancheng]> create view s as select * from students where Age < 20;

Query OK, 0 rows affected (0.09 sec)

MySQL [yuancheng]>

查看全部表是否有s表

MySQL [yuancheng]> show tables;

+---------------------+

| Tables_in_yuancheng |

+---------------------+

| classes |

| coc |

| courses |

| s |

| scores |

| students |

| teachers |

| toc |

+---------------------+

8 rows in set (0.03 sec)

MySQL [yuancheng]>

查看s表中的數據是否知足條件

MySQL [yuancheng]> select * from s;

+-------+--------------+-----+--------+---------+-----------+

+-------+--------------+-----+--------+---------+-----------+

| 7 | Xi Ren | 19 | F | 3 | 6 |

| 8 | Lin Daiyu | 17 | F | 7 | 6 |

| 10 | Yue Lingshan | 19 | F | 3 | 6 |

| 12 | Wen Qingqing | 19 | F | 1 | 2 |

| 14 | Lu Wushuang | 17 | F | 3 | 6 |

| 15 | Duan Yu | 19 | M | 4 | 6 |

| 19 | Xue Baochai | 18 | F | 6 | 6 |

| 20 | Diao Chan | 19 | F | 7 | 6 |

+-------+--------------+-----+--------+---------+-----------+

8 rows in set (0.02 sec)

MySQL [yuancheng]>

在上面的代碼語句中建立了一個名爲s的視圖，經過對代碼的觀察能夠發現，實際上sql語句裏寫的就是一個表查詢語句，只不過是把這個查詢語句封裝起來從新起了一個別名，以便之後能夠重複使用。

2.2、建立各類視圖

因爲視圖的功能其實是封裝查詢語句，那麼是否是任何形式的查詢語句均可以封裝在視圖裏面呢，經過實例介紹各類形式的視圖。

2.2.1、建立查詢常量語句的視圖，即常量視圖

mysql> create view view_test1 as select 3;

Query OK, 0 rows affected (0.02 sec)

mysql> select * from view_test1;

+---+

| 3 |

+---+

| 3 |

+---+

1 row in set (0.02 sec)

mysql>

2.2.2、建立聚合函數視圖

好比 sum 、max、min、count等

mysql> create view view_test2 as select sum(Age) from students;

Query OK, 0 rows affected (0.03 sec)

mysql> select * from view_test2;

+----------+

| sum(Age) |

+----------+

| 670 |

+----------+

1 row in set (0.01 sec)

mysql>

2.2.3、建立排序功能（order by）的查詢語句功能

mysql> create view view_test4 as select * from students where Age<=19 order by Age desc;

Query OK, 0 rows affected (0.02 sec)

mysql>

mysql> select * from view_test4;

+-------+--------------+-----+--------+---------+-----------+

+-------+--------------+-----+--------+---------+-----------+

| 7 | Xi Ren | 19 | F | 3 | 6 |

| 10 | Yue Lingshan | 19 | F | 3 | 6 |

| 12 | Wen Qingqing | 19 | F | 1 | 2 |

| 15 | Duan Yu | 19 | M | 4 | 6 |

| 20 | Diao Chan | 19 | F | 7 | 6 |

| 19 | Xue Baochai | 18 | F | 6 | 6 |

| 8 | Lin Daiyu | 17 | F | 7 | 6 |

| 14 | Lu Wushuang | 17 | F | 3 | 6 |

+-------+--------------+-----+--------+---------+-----------+

8 rows in set (0.01 sec)

mysql>

2.2.4、建立內鏈接查詢語句視圖

mysql> create view view_deal as SELECT farmer_deal_record.order_id ,order_info.create_time ,vendor.`name` ,(CASE vendor.type WHEN 1 THEN '營' WHEN 2 THEN '營' END),vendor.real_name,vendor.phone ,operator.`name` ,operator.phone,farmer_deal_record.farmer_id ,(CASE farmer.vendor WHEN 0 THEN '否' WHEN 1 THEN '是' END) ,farmer.`name` ,farmer.phone , order_info.contact_name ,order_info.contact_phone ,order_info.crop ,order_info.fee_real ,order_info.area_real,farmer_deal_record.pay_type ,farmer_deal_record.deal_type ,farmer_deal_record.deal_time ,farmer_deal_record.amount ,farmer_deal_record.fee_deal, farmer_deal_record.deduction FROM farmer_deal_record,order_info,vendor,farmer,operator_order,operator WHERE NOT deal_type=102 AND farmer_deal_record.order_id=order_info.id AND order_info.vendor_id=vendor.id AND farmer_deal_record.farmer_id=farmer.id AND order_info.id=operator_order.order_id AND operator_order.operator_id=operator.id ORDER BY farmer_deal_record.deal_time,vendor.`name` DESC ;

Query OK, 0 rows affected (0.00 sec)

mysql>

mysql> select * from view_deal;

+--------------------+---------------------+--------------------------------------------+--------------------+--------------------+--------------------------+--------------+--------------------+----------+--------------------+--------------+--------------+-----------------+-----------------------+-----------+--------------+--------------+--------------+--------------+---------------------+-----------+--------------+--------------------+

| 152247404135 | 2018-03-31 13:29:26 | 中心 | 直營 | 嚴 | 1827 | 劉 | 1686 | 94 | 否 | NULL | 676 | 由 | 13312345678 | 稻 | 0.01 | 1.00 | 1 | 99 | 2018-03-31 15:58:02 | 0.01 | 0.01 | 0.00 |

| 152248060 | 2018-03-31 16:00:42 | 心 | 直營 | 瑋 | 1527 | 愷 | 1386 | 94 | 否 | NULL | 1776 | 袁 | 17310376676 | 稻 | 0.01 | 0.96 | 2 | 99 | 2018-03-31 16:10:55 | 0.01 | 0.01 | 0.00 |

| 1559 | 2018-04-20 22:08:52 | 心 | 營 | 長 | 145 | 成 | 151345 | 98 | 否 | NULL | 145 | 成 | 15072371345 | 麥 | 2420.00 | 242.00 | 1 | 99 | 2018-04-20 22:28:41 | 2420.00 | 2420.00 | 0.00 |

+-----------------------------------------------------------------------------------------------------------------------------+

2.2.5、建立外連接（LEFT JOIN 和RIGHT JOIN）查詢語句視圖

mysql> create view view_test5 as SELECT StuID,teachers.Name FROM students LEFT JOIN teachers ON students.TeacherID=teachers.TID;

Query OK, 0 rows affected (0.02 sec)

mysql>

2.2.6、建立聯合查詢（UNION 和UNION ALL）語句的視圖

mysql> create view view_test6 as select Name from students union all select Name from teachers;;

Query OK, 0 rows affected (0.03 sec)

mysql>

mysql> select * from view_test6;

+----------------+

| Name |

+----------------+

| Shi Zhongyu |

| Shi Potian |

| Xie Yanke |

| Ding Dian |

| Yu Yutong |

| Shi Qing |

| Xi Ren |

| Lin Daiyu |

| Ren Yingying |

| Yue Lingshan |

| Yuan Chengzhi |

| Wen Qingqing |

| Tian Boguang |

| Lu Wushuang |

| Duan Yu |

| Xu Zhu |

| Lin Chong |

| Hua Rong |

| Xue Baochai |

| Diao Chan |

| Huang Yueying |

| Xiao Qiao |

| Ma Chao |

| Xu Xian |

| Sun Dasheng |

| Shi Jin |

| Liu Bei |

| Lu Zhi |

| Zhu Ge Liang |

| Huang Yue Ying |

| Zhao Yun |

| Pang Tong |

+----------------+

32 rows in set (0.03 sec)

mysql>

2.3、查看視圖

建立完視圖後，常常會查詢視圖信息，在mysql中可使用 SHOW TABLES 、SHOW TABLE STATUS、SHOW CTRATE VIEW等語句查詢數據，若是使用這些語句來查詢，首先要確保擁有SHOW VIEW的權限。

2.3.1、使用SHOW TABLES語句查看視圖名

經過SHOW TABLES語句查看數據庫中的表和視圖的表

mysql> show tables;

+---------------------+

| Tables_in_yuancheng |

+---------------------+

| classes |

| coc |

| courses |

| s |

| scores |

| students |

| teachers |

| toc |

| view_test1 |

| view_test2 |

| view_test3 |

| view_test4 |

| view_test5 |

| view_test6 |

+---------------------+

14 rows in set (0.02 sec)

mysql>

2.3.2、使用SHOW TABLE STATUS語句查看視圖或表的詳細信息

SHOW TABLE STATUS [LIKE TABLE_NAME];

mysql> show table status like 'wx_order' \G;

*************************** 1. row ***************************

Name: wx_order

Engine: InnoDB

Version: 10

Row_format: Compact

Rows: 43

Avg_row_length: 381

Data_length: 16384

Max_data_length: 0

Index_length: 0

Data_free: 0

Auto_increment: 52

Create_time: 2018-05-16 17:02:05

Update_time: NULL

Check_time: NULL

Collation: utf8mb4_general_ci

Checksum: NULL

Create_options:

Comment: 微信支付訂單

1 row in set (0.00 sec)

ERROR:

No query specified

mysql>

注：其中各個字段的含義以下：

2.3.3、使用SHOW CREATE VIEW 語句查看視圖定義信息

若是想查看關於建立視圖的定義信息，能夠經過SHOW CREATE VIEW 語句來實現，語法爲：

SHOW CREATE VIEW view_name

上述參數中view_name參數爲表示要查看定義信息的視圖名稱。

【例子1】查看view_test1的定義信息

mysql> show create view view_test3;

+------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+

| view_test3 | CREATE ALGORITHM=UNDEFINED DEFINER=`zhang`@`%` SQL SECURITY DEFINER VIEW `view_test3` AS select `students`.`StuID` AS `StuID`,`students`.`Name` AS `Name`,`students`.`Age` AS `Age`,`students`.`Gender` AS `Gender`,`students`.`ClassID` AS `ClassID`,`students`.`TeacherID` AS `TeacherID` from `students` where (`students`.`Age` < 15) order by `students`.`Age` desc | utf8 | utf8_general_ci |

1 row in set (0.02 sec)

mysql> show create view view_test3\G;

*************************** 1. row ***************************

View: view_test3

Create View: CREATE ALGORITHM=UNDEFINED DEFINER=`zhang`@`%` SQL SECURITY DEFINER VIEW `view_test3` AS select `students`.`StuID` AS `StuID`,`students`.`Name` AS `Name`,`students`.`Age` AS `Age`,`students`.`Gender` AS `Gender`,`students`.`ClassID` AS `ClassID`,`students`.`TeacherID` AS `TeacherID` from `students` where (`students`.`Age` < 15) order by `students`.`Age` desc

character_set_client: utf8

collation_connection: utf8_general_ci

1 row in set (0.02 sec)

ERROR:

No query specified

mysql>

2.3.4、使用DESC語句查看錶結構

若是想查看關於視圖的表結構能夠經過DESC語句來查看。

mysql> desc view_test3;

+-----------+---------------------+------+-----+---------+-------+

+-----------+---------------------+------+-----+---------+-------+

| StuID | int(10) unsigned | NO | | 0 | |

| Age | tinyint(3) unsigned | NO | | NULL | |

+-----------+---------------------+------+-----+---------+-------+

6 rows in set (0.02 sec)

mysql>

2.3.5、經過系統表查看視圖信息

當mysql數據庫安裝成功後，會自動建立系統數據庫information_schema，在該數據庫中存在一個包含視圖信息的表views，能夠經過查看錶views來查看相關信息。以下：

mysql> use information_schema;

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

mysql>

mysql> select * from views where table_name='view_test3'\G;

*************************** 1. row ***************************

TABLE_CATALOG: def

TABLE_SCHEMA: yuancheng

TABLE_NAME: view_test3

VIEW_DEFINITION: select `yuancheng`.`students`.`StuID` AS `StuID`,`yuancheng`.`students`.`Name` AS `Name`,`yuancheng`.`students`.`Age` AS `Age`,`yuancheng`.`students`.`Gender` AS `Gender`,`yuancheng`.`students`.`ClassID` AS `ClassID`,`yuancheng`.`students`.`TeacherID` AS `TeacherID` from `yuancheng`.`students` where (`yuancheng`.`students`.`Age` < 15) order by `yuancheng`.`students`.`Age` desc

CHECK_OPTION: NONE

IS_UPDATABLE: YES

DEFINER: zhang@%

SECURITY_TYPE: DEFINER

CHARACTER_SET_CLIENT: utf8

COLLATION_CONNECTION: utf8_general_ci

1 row in set (0.03 sec)

ERROR:

No query specified

mysql>

2.4、刪除視圖

視圖的操做包括建立視圖、查看視圖、刪除視圖和修改視圖。在刪除視圖時，要確保擁有DROP VIEW 的權限。

2.4.1、刪除視圖

在刪除視圖時課堂經過DROP VIEW語句刪除一個或者多個視圖，語法格式以下：

DROP VIEW View_name [,View_name]….

在上述語句中，view_name參數是要刪除視圖的名稱

【列子1】刪除view_test1視圖

mysql> show tables;

+---------------------+

| Tables_in_yuancheng |

+---------------------+

| classes |

| coc |

| courses |

| s |

| scores |

| students |

| teachers |

| toc |

| view_test1 |

| view_test2 |

| view_test3 |

| view_test4 |

| view_test5 |

| view_test6 |

+---------------------+

14 rows in set (0.02 sec)

mysql> drop view view_test1;

Query OK, 0 rows affected (0.02 sec)

mysql> show tables;

+---------------------+

| Tables_in_yuancheng |

+---------------------+

| classes |

| coc |

| courses |

| s |

| scores |

| students |

| teachers |

| toc |

| view_test2 |

| view_test3 |

| view_test4 |

| view_test5 |

| view_test6 |

+---------------------+

13 rows in set (0.02 sec)

mysql>

【例子2】刪除多個視圖

mysql> drop view s,view_test4,view_test3;

Query OK, 0 rows affected (0.02 sec)

mysql>

mysql> show tables;

+---------------------+

| Tables_in_yuancheng |

+---------------------+

| classes |

| coc |

| courses |

| scores |

| students |

| teachers |

| toc |

| view_test2 |

| view_test5 |

| view_test6 |

+---------------------+

10 rows in set (0.02 sec)

mysql>

2.5、修改視圖

對於已經已經建立好的視圖，在使用過一段時間以後，若是須要進行一些表結構上的修改，即視圖的修改，除了可使用ALTER語句實現修改視圖以外還能夠經過CREATE OR REPLACE VIEW語句來修改視圖。

對於已經建立好的表，尤爲是已經有大量數據的表。經過先刪除，而後按照新的表定義重建表的方式來修改表時，須要作許多額外的工做，好比數據的從新加載等，對於視圖來講，自己就是一張‘虛表’，並無實質性存儲數據，全部能夠經過該方式來修改視圖。

2.5.1、CREATE OR REPLACE VIEW 語句修改視圖

l 建立視圖view_1

mysql> create view view_1 as select students.StuID,students.Name,students.Age from students,teachers where students.TeacherID=teachers.TID and students.Age<20;

Query OK, 0 rows affected (0.01 sec)

mysql>

l 查看視圖內容

mysql> select * from view_1;

+-------+--------------+-----+

| StuID | Name | Age |

+-------+--------------+-----+

| 12 | Wen Qingqing | 19 |

| 7 | Xi Ren | 19 |

| 8 | Lin Daiyu | 17 |

| 10 | Yue Lingshan | 19 |

| 14 | Lu Wushuang | 17 |

| 15 | Duan Yu | 19 |

| 19 | Xue Baochai | 18 |

| 20 | Diao Chan | 19 |

+-------+--------------+-----+

8 rows in set (0.01 sec)

mysql>

l 修改視圖

mysql> create or replace view view_1 as select students.StuID,students.Name,students.Age,students.ClassID,teachers.name as Tname from students,teachers where students.TeacherID=teachers.TID and students.Age<<20;

Query OK, 0 rows affected (0.02 sec)

mysql>

l 查看修改後的視圖內容

mysql> select * from view_1;

+-------+--------------+-----+---------+-----------+

+-------+--------------+-----+---------+-----------+

| 12 | Wen Qingqing | 19 | 1 | Lu Zhi |

| 7 | Xi Ren | 19 | 3 | Pang Tong |

| 8 | Lin Daiyu | 17 | 7 | Pang Tong |

| 10 | Yue Lingshan | 19 | 3 | Pang Tong |

| 14 | Lu Wushuang | 17 | 3 | Pang Tong |

| 15 | Duan Yu | 19 | 4 | Pang Tong |

| 19 | Xue Baochai | 18 | 6 | Pang Tong |

| 20 | Diao Chan | 19 | 7 | Pang Tong |

+-------+--------------+-----+---------+-----------+

8 rows in set (0.01 sec)

mysql>

2.5.2、ALTER語句修改視圖

使用ALTER語句來修改視圖，其語法格式以下：

ALTER VIEW View_Name AS 查詢語句

【例子1】經過2.5.1上面的視圖添加查詢字段名稱

mysql> alter view view_1 as select students.StuID,students.Name,students.Age,students.ClassID,teachers.name as Tname,teachers.Age as TAge,teachers.Gender as TGender from students,teachers where students.TeachherID=teachers.TID and students.Age<20;

Query OK, 0 rows affected (0.02 sec)

mysql> select * from view_1;

+-------+--------------+-----+---------+-----------+------+---------+

+-------+--------------+-----+---------+-----------+------+---------+

| 12 | Wen Qingqing | 19 | 1 | Lu Zhi | 30 | F |

| 7 | Xi Ren | 19 | 3 | Pang Tong | 44 | F |

| 8 | Lin Daiyu | 17 | 7 | Pang Tong | 44 | F |

| 10 | Yue Lingshan | 19 | 3 | Pang Tong | 44 | F |

| 14 | Lu Wushuang | 17 | 3 | Pang Tong | 44 | F |

| 15 | Duan Yu | 19 | 4 | Pang Tong | 44 | F |

| 19 | Xue Baochai | 18 | 6 | Pang Tong | 44 | F |

| 20 | Diao Chan | 19 | 7 | Pang Tong | 44 | F |

+-------+--------------+-----+---------+-----------+------+---------+

8 rows in set (0.01 sec)

mysql>

2.6、利用視圖操做基本表

在mysql中能夠經過視圖檢索（查詢）基本表數據，除此以外還能夠經過視圖修改基本表中的數據。

2.6.1、查詢數據

經過視圖查詢數據，與經過表查詢數據徹底相同，經過視圖查詢比表更安全，簡單和實用。只需在查詢時把表名換成視圖名稱便可

【例子1】查詢視圖信息

mysql> select * from view_1;

+-------+--------------+-----+---------+-----------+------+---------+

+-------+--------------+-----+---------+-----------+------+---------+

| 12 | Wen Qingqing | 19 | 1 | Lu Zhi | 30 | F |

| 7 | Xi Ren | 19 | 3 | Pang Tong | 44 | F |

| 8 | Lin Daiyu | 17 | 7 | Pang Tong | 44 | F |

| 10 | Yue Lingshan | 19 | 3 | Pang Tong | 44 | F |

| 14 | Lu Wushuang | 17 | 3 | Pang Tong | 44 | F |

| 15 | Duan Yu | 19 | 4 | Pang Tong | 44 | F |

| 19 | Xue Baochai | 18 | 6 | Pang Tong | 44 | F |

| 20 | Diao Chan | 19 | 7 | Pang Tong | 44 | F |

+-------+--------------+-----+---------+-----------+------+---------+

8 rows in set (0.01 sec)

mysql>

2.6.2、利用視圖操做基本表數據

經過建立的視圖不只能夠對視圖進行查詢數據，並且還能夠對視圖進行更新（增長、刪除和更新）數據操做。因爲視圖是虛表，因此對視圖數據進行的更新操做，其實是對其基本表數據進行更新操做。在具體更新視圖數據時，須要注意如下兩點：

l 對視圖數據進行添加、刪除和更新操做直接影響基本表。

l 視圖來自多個基本表時，不容許添加和刪除數據。

2.6.2.1、添加數據

mysql> create view view_1 as select * from students where Age < 20;

Query OK, 0 rows affected (0.02 sec)

mysql> select * from view_1;

+-------+--------------+-----+--------+---------+-----------+

+-------+--------------+-----+--------+---------+-----------+

| 7 | Xi Ren | 19 | F | 3 | 6 |

| 8 | Lin Daiyu | 17 | F | 7 | 6 |

| 10 | Yue Lingshan | 19 | F | 3 | 6 |

| 12 | Wen Qingqing | 19 | F | 1 | 2 |

| 14 | Lu Wushuang | 17 | F | 3 | 6 |

| 15 | Duan Yu | 19 | M | 4 | 6 |

| 19 | Xue Baochai | 18 | F | 6 | 6 |

| 20 | Diao Chan | 19 | F | 7 | 6 |

+-------+--------------+-----+--------+---------+-----------+

8 rows in set (0.02 sec)

mysql>

mysql> insert into view_1 (StuID,Name,Age,Gender,ClassID,TeacherID) values(27,'Zhang Wang',10,''F',3,2);

Query OK, 1 row affected (0.01 sec)

mysql> select * from view_1;

+-------+--------------+-----+--------+---------+-----------+

+-------+--------------+-----+--------+---------+-----------+

| 7 | Xi Ren | 19 | F | 3 | 6 |

| 8 | Lin Daiyu | 17 | F | 7 | 6 |

| 10 | Yue Lingshan | 19 | F | 3 | 6 |

| 12 | Wen Qingqing | 19 | F | 1 | 2 |

| 14 | Lu Wushuang | 17 | F | 3 | 6 |

| 15 | Duan Yu | 19 | M | 4 | 6 |

| 19 | Xue Baochai | 18 | F | 6 | 6 |

| 20 | Diao Chan | 19 | F | 7 | 6 |

| 27 | Zhang Wang | 10 | F | 3 | 2 |

+-------+--------------+-----+--------+---------+-----------+

9 rows in set (0.02 sec)

mysql>

注意：VALUSE後的數據常量與視圖中的列要一一對應

2.6.2.2、刪除數據操做

mysql> select * from view_1;

+-------+--------------+-----+--------+---------+-----------+

+-------+--------------+-----+--------+---------+-----------+

| 7 | Xi Ren | 19 | F | 3 | 6 |

| 8 | Lin Daiyu | 17 | F | 7 | 6 |

| 10 | Yue Lingshan | 19 | F | 3 | 6 |

| 12 | Wen Qingqing | 19 | F | 1 | 2 |

| 14 | Lu Wushuang | 17 | F | 3 | 6 |

| 15 | Duan Yu | 19 | M | 4 | 6 |

| 19 | Xue Baochai | 18 | F | 6 | 6 |

+-------+--------------+-----+--------+---------+-----------+

7 rows in set (0.01 sec)

mysql> delete from view_1 where StuID=19 or StuID=12;

Query OK, 2 rows affected (0.02 sec)

mysql> select * from view_1;

+-------+--------------+-----+--------+---------+-----------+

+-------+--------------+-----+--------+---------+-----------+

| 7 | Xi Ren | 19 | F | 3 | 6 |

| 8 | Lin Daiyu | 17 | F | 7 | 6 |

| 10 | Yue Lingshan | 19 | F | 3 | 6 |

| 14 | Lu Wushuang | 17 | F | 3 | 6 |

| 15 | Duan Yu | 19 | M | 4 | 6 |

+-------+--------------+-----+--------+---------+-----------+

5 rows in set (0.01 sec)

mysql>

2.6.2.3、更新數據

mysql> update view_1 set Age='15' where Name='Duan Yu' and Age=19;

Query OK, 1 row affected (0.01 sec)

Rows matched: 1 Changed: 1 Warnings: 0

mysql> select * from view_1;

+-------+--------------+-----+--------+---------+-----------+

+-------+--------------+-----+--------+---------+-----------+

| 7 | Xi Ren | 19 | F | 3 | 6 |

| 8 | Lin Daiyu | 17 | F | 7 | 6 |

| 10 | Yue Lingshan | 19 | F | 3 | 6 |

| 14 | Lu Wushuang | 17 | F | 3 | 6 |

| 15 | Duan Yu | 15 | M | 4 | 6 |

+-------+--------------+-----+--------+---------+-----------+

5 rows in set (0.01 sec)

mysql>

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