mysql創建用戶、賦權限、以及刪除用戶

1.創建用戶

mysql> create user 'username'@'localhost/%/ip' identified by 'password';
Query OK, 0 rows affected (0.05 sec)
// 說明 localhost/%/ip ，可以指定ip（限定ip訪問），localhost（本服務器訪問）以及%（不限制ip訪問）

2.賦予權限

mysql> grant select/update/insert/delete/alter/drop/create(能是一個或多個權限) on *.* to 'username'@'localhost/ip/%';
Query OK, 0 rows affected (0.01 sec)

3.刪除用戶delete和drop兩種刪除

推薦使用drop以防ERROR 1396 (HY000): Operation CREATE USER failed for 'username'@'password'

方式一：
mysql> delete from user where user='username' and host='localhost';
Query OK, 1 row affected (0.02 sec)
mysql> flush privileges; // 記得刷新權限表，如果不刷新的話，直接創建相同用戶會報錯。
Query OK, 0 rows affected (0.01 sec)

方式二：
mysql> drop user 'username'@'localhost';
Query OK, 0 rows affected (0.00 sec)

錯誤：
mysql> delete from user where user='username' and host='localhost';
Query OK, 1 row affected (0.02 sec)
mysql> create user 'username'@'localhost' identified by 'password';
ERROR 1396 (HY000): Operation CREATE USER failed for 'username'@'password'
解決：
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> create user 'username'@'localhost' identified by 'password';
Query OK, 0 rows affected (0.00 sec)