DROP USER
此语句用于从 TiDB 系统数据库中删除一个用户。可选的关键字 IF EXISTS 可以用来避免在用户不存在时产生错误。执行此操作需要拥有 CREATE USER 权限。
概述
- DropUserStmt
- Username
DropUserStmt ::=
'DROP' 'USER' ( 'IF' 'EXISTS' )? UsernameList
Username ::=
StringName ('@' StringName | singleAtIdentifier)? | 'CURRENT_USER' OptionalBraces
示例
mysql> DROP USER idontexist;
ERROR 1396 (HY000): Operation DROP USER failed for idontexist@%
mysql> DROP USER IF EXISTS 'idontexist';
Query OK, 0 rows affected (0.01 sec)
mysql> CREATE USER 'newuser' IDENTIFIED BY 'mypassword';
Query OK, 1 row affected (0.02 sec)
mysql> GRANT ALL ON test.* TO 'newuser';
Query OK, 0 rows affected (0.03 sec)
mysql> SHOW GRANTS FOR 'newuser';
+-------------------------------------------------+
| Grants for newuser@% |
+-------------------------------------------------+
| GRANT USAGE ON *.* TO 'newuser'@'%' |
| GRANT ALL PRIVILEGES ON test.* TO 'newuser'@'%' |
+-------------------------------------------------+
2 rows in set (0.00 sec)
mysql> REVOKE ALL ON test.* FROM 'newuser';
Query OK, 0 rows affected (0.03 sec)
mysql> SHOW GRANTS FOR 'newuser';
+-------------------------------------+
| Grants for newuser@% |
+-------------------------------------+
| GRANT USAGE ON *.* TO 'newuser'@'%' |
+-------------------------------------+
1 row in set (0.00 sec)
mysql> DROP USER 'newuser';
Query OK, 0 rows affected (0.14 sec)
mysql> SHOW GRANTS FOR 'newuser';
ERROR 1141 (42000): There is no such grant defined for user 'newuser' on host '%'
MySQL 兼容性
- 使用
IF EXISTS删除不存在的用户在 TiDB 中不会产生警告。Issue #10196。