查看mysql已有用户并删除

查看：

SELECT DISTINCT CONCAT('User: ''',user,'''@''',host,''';') AS query FROM mysql.user;

删除：

drop user 'username'@'host';

mysql> SELECT DISTINCT CONCAT('User: ''',user,'''@''',host,''';') AS query FROM mysql.user;
+-----------------------------------+
| query                             |
+-----------------------------------+
| User: 'root'@'127.0.0.1';         |
| User: 'slaveuser'@'192.168.15.%'; |
| User: 'root'@'::1';               |
| User: 'username'@'host';          |
| User: ''@'localhost';             |
| User: 'root'@'localhost';         |
| User: ''@'vm-linux-t';            |
| User: 'root'@'vm-linux-t';        |
+-----------------------------------+
8 rows in set (0.00 sec)

mysql> drop user 'username'@'host';
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT DISTINCT CONCAT('User: ''',user,'''@''',host,''';') AS query FROM mysql.user;
+-----------------------------------+
| query                             |
+-----------------------------------+
| User: 'root'@'127.0.0.1';         |
| User: 'slaveuser'@'192.168.15.%'; |
| User: 'root'@'::1';               |
| User: ''@'localhost';             |
| User: 'root'@'localhost';         |
| User: ''@'vm-linux-t';            |
| User: 'root'@'vm-linux-t';        |
+-----------------------------------+
7 rows in set (0.00 sec)

mysql>