MySQL权限篇之DELETE及SELECT

DELETE权限，该权限仅仅能删除表中的记录。

但是要注意如果仅仅只授予了DELETE权限。

比如：

mysql> show grants for 'ut01'@'%';

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

| Grants for ut01@%                |

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

| GRANT USAGE ON *.* TO 'ut01'@'%' |

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

1 row in set (0.00 sec)

mysql> grant delete on test.t1 to 'ut01'@'%';  #在test.t1表上有delete权限

Query OK, 0 rows affected (0.03 sec)

mysql> use test

Database changed

mysql> insert into t1 values(1),(2),(3);

Query OK, 3 rows affected (0.12 sec)

Records: 3  Duplicates: 0  Warnings: 0

mysql>

那么请问ut01@%用户执行 delete from  t1 where id=3; 能够成功吗？

答案是不会的。因为该用户没有id列上的select权限，所以会由于where子句而失败。

下面来看：

C:\Users\Administrator>mysql -uut01

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 21

Server version: 5.7.11-log MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use test

Database changed

mysql> show tables;

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

| Tables_in_test |

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

| t1             |

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

1 row in set (0.00 sec)

mysql> desc t1;

Empty set (0.00 sec)

mysql> select * from t1;

ERROR 1142 (42000): SELECT command denied to user 'ut01'@'localhost' for table 't1'

mysql> delete from t1 where t1.id=3;

ERROR 1143 (42000): SELECT command denied to user 'ut01'@'localhost' for column 'id' in table 't1'

mysql> delete from t1;

Query OK, 3 rows affected (0.09 sec)

mysql> delete from t1 where 1=1;

Query OK, 0 rows affected (0.05 sec)

mysql>

不加where条件的delete可以删除成功。

SELECT权限，很好理解。就是可以对某个库的某个表的某个列（或者所有列）的查询权限。

不演示。但是下面的SELECT查询并不需要SELECT权限：

SELECT 1+1;
SELECT PI()*2;