MySql视图

时间 2019-12-19

标签 mysql 视图栏目 MySQL 繁體版

原文原文链接

MySql视图mysql

1、为何使用视图

在数据库中关于数据的查询有时候很是麻烦，例如表链接、子查询等，这种查询会很是痛苦，由于逻辑比较复杂、编写语句比较多。当这种查询须要重复使用时，则不会每次都能编写正确，从而下降了数据库的实用性。sql

在具体操做表前，有时候要求只能操做部分字段，而不是所有字段。数据库

为了提升复杂sql语句的复用性和表操做的安全性，mysql数据库管理系统提供视图特性。所谓的视图，本质上是一种虚拟表，其内容与真实的表类似，包含一系列带有名称的列和行数据。可是，视图并不在数据库中以存储的数据值形式存在。行和列的数据来自自定义视图的查询所引用的基本表，而且在具体引用视图时动态生成。安全

视图主要关注某些特定数据和他们所查询的数据内容，这样只能看到视图中所定义的数据，而不是视图所引用表中的数据，从而提升了数据库中数据的安全性。微信

视图的特色以下：ide

l 视图的列能够来自不一样的表，是表的抽象和在逻辑意义上创建的新关系函数

l 视图是由基本表（实表）产生的表（虚表）微信支付

l 视图的创建和删除不影响基本表ui

l 对视图内容的更新（添加、删除和修改）直接影响基本表this

l 当视图来自多个基本表时，不容许添加和删除数据

2、建立视图

视图的操做包括建立视图，查看视图、删除视图和修改视图。在建立视图时，首先要确保拥有CREATE VIEW的权限，而且同时确保对建立视图所引用的表也具备相应的权限。

2.1、建立视图的语法形式

虽然视图能够被当作是一种虚拟表，可是在其物理上是不存在的，即数据库管理系统没有专门的位置为视图存储数据。根据视图的概念能够发现其数据来源于查询语句，所以建立视图的语法为：

CREATE VIEW VIEW_NAME AS 查询语句

和建立表同样，视图名不能和表名、也不能和其余的视图名称重名。根据上述语法能够发现，视图的功能实际上就是封装了复杂的查询语句。

注：在SQL语句命名规范中，视图通常以view_XXX或者v_XXX的样式来命名。例子以下：

【列子1】建立students表中年龄小于20的视图名字为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表中的数据是否知足条件

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]>

在上面的代码语句中建立了一个名为s的视图，经过对代码的观察能够发现，实际上sql语句里写的就是一个表查询语句，只不过是把这个查询语句封装起来从新起了一个别名，以便之后能够重复使用。

2.2、建立各类视图

因为视图的功能其实是封装查询语句，那么是否是任何形式的查询语句均可以封装在视图里面呢，经过实例介绍各类形式的视图。

2.2.1、建立查询常量语句的视图，即常量视图

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、建立聚合函数视图

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）的查询语句功能

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、建立内链接查询语句视图

mysql> create view view_deal as SELECT farmer_deal_record.order_id ,order_info.create_time ,vendor.`name` ,(CASE vendor.type WHEN 1 THEN '营' WHEN 2 THEN '营' 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 | 直营 | 严 | 1827 | 刘 | 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 | 直营 | 玮 | 1527 | 恺 | 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 | 营 | 长 | 145 | 成 | 151345 | 98 | 否 | NULL | 145 | 成 | 15072371345 | 麦 | 2420.00 | 242.00 | 1 | 99 | 2018-04-20 22:28:41 | 2420.00 | 2420.00 | 0.00 |

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

2.2.5、建立外连接（LEFT JOIN 和RIGHT JOIN）查询语句视图

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、建立联合查询（UNION 和UNION ALL）语句的视图

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、查看视图

建立完视图后，常常会查询视图信息，在mysql中可使用 SHOW TABLES 、SHOW TABLE STATUS、SHOW CTRATE VIEW等语句查询数据，若是使用这些语句来查询，首先要确保拥有SHOW VIEW的权限。

2.3.1、使用SHOW TABLES语句查看视图名

经过SHOW TABLES语句查看数据库中的表和视图的表

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语句查看视图或表的详细信息

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: 微信支付订单

1 row in set (0.00 sec)

ERROR:

No query specified

mysql>

注：其中各个字段的含义以下：

2.3.3、使用SHOW CREATE VIEW 语句查看视图定义信息

若是想查看关于建立视图的定义信息，能够经过SHOW CREATE VIEW 语句来实现，语法为：

SHOW CREATE VIEW view_name

上述参数中view_name参数为表示要查看定义信息的视图名称。

【例子1】查看view_test1的定义信息

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语句查看表结构

若是想查看关于视图的表结构能够经过DESC语句来查看。

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、经过系统表查看视图信息

当mysql数据库安装成功后，会自动建立系统数据库information_schema，在该数据库中存在一个包含视图信息的表views，能够经过查看表views来查看相关信息。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、删除视图

视图的操做包括建立视图、查看视图、删除视图和修改视图。在删除视图时，要确保拥有DROP VIEW 的权限。

2.4.1、删除视图

在删除视图时课堂经过DROP VIEW语句删除一个或者多个视图，语法格式以下：

DROP VIEW View_name [,View_name]….

在上述语句中，view_name参数是要删除视图的名称

【列子1】删除view_test1视图

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】删除多个视图

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、修改视图

对于已经已经建立好的视图，在使用过一段时间以后，若是须要进行一些表结构上的修改，即视图的修改，除了可使用ALTER语句实现修改视图以外还能够经过CREATE OR REPLACE VIEW语句来修改视图。

对于已经建立好的表，尤为是已经有大量数据的表。经过先删除，而后按照新的表定义重建表的方式来修改表时，须要作许多额外的工做，好比数据的从新加载等，对于视图来讲，自己就是一张‘虚表’，并无实质性存储数据，全部能够经过该方式来修改视图。

2.5.1、CREATE OR REPLACE VIEW 语句修改视图

l 建立视图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 查看视图内容

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 修改视图

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 查看修改后的视图内容

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语句修改视图

使用ALTER语句来修改视图，其语法格式以下：

ALTER VIEW View_Name AS 查询语句

【例子1】经过2.5.1上面的视图添加查询字段名称

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、利用视图操做基本表

在mysql中能够经过视图检索（查询）基本表数据，除此以外还能够经过视图修改基本表中的数据。

2.6.1、查询数据

经过视图查询数据，与经过表查询数据彻底相同，经过视图查询比表更安全，简单和实用。只需在查询时把表名换成视图名称便可

【例子1】查询视图信息

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、利用视图操做基本表数据

经过建立的视图不只能够对视图进行查询数据，并且还能够对视图进行更新（增长、删除和更新）数据操做。因为视图是虚表，因此对视图数据进行的更新操做，其实是对其基本表数据进行更新操做。在具体更新视图数据时，须要注意如下两点：

l 对视图数据进行添加、删除和更新操做直接影响基本表。

l 视图来自多个基本表时，不容许添加和删除数据。

2.6.2.1、添加数据

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后的数据常量与视图中的列要一一对应

2.6.2.2、删除数据操做

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、更新数据

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>