ALTER USER

此语句用于修改 TiDB 权限系统中的现有用户。在 MySQL 权限系统中，用户是用户名和连接来源主机的组合。因此，可以创建一个 'newuser2'@'192.168.1.1' 用户，该用户只能从 IP 地址 192.168.1.1 连接。也可以让两个用户具有相同的用户部分，但登录自不同的主机时拥有不同的权限。

概述

AlterUserStmt ::=
    'ALTER' 'USER' IfExists (UserSpecList RequireClauseOpt ConnectionOptions PasswordOption LockOption AttributeOption | 'USER' '(' ')' 'IDENTIFIED' 'BY' AuthString) ResourceGroupNameOption

UserSpecList ::=
    UserSpec ( ',' UserSpec )*

UserSpec ::=
    Username AuthOption

RequireClauseOpt ::=
    ( 'REQUIRE' 'NONE' | 'REQUIRE' 'SSL' | 'REQUIRE' 'X509' | 'REQUIRE' RequireList )?

RequireList ::=
    ( "ISSUER" stringLit | "SUBJECT" stringLit | "CIPHER" stringLit | "SAN" stringLit | "TOKEN_ISSUER" stringLit )*

Username ::=
    StringName ('@' StringName | singleAtIdentifier)? | 'CURRENT_USER' OptionalBraces

AuthOption ::=
    ( 'IDENTIFIED' ( 'BY' ( AuthString | 'PASSWORD' HashString ) | 'WITH' StringName ( 'BY' AuthString | 'AS' HashString )? ) )?

PasswordOption ::= ( 'PASSWORD' 'EXPIRE' ( 'DEFAULT' | 'NEVER' | 'INTERVAL' N 'DAY' )? | 'PASSWORD' 'HISTORY' ( 'DEFAULT' | N ) | 'PASSWORD' 'REUSE' 'INTERVAL' ( 'DEFAULT' | N 'DAY' ) | 'FAILED_LOGIN_ATTEMPTS' N | 'PASSWORD_LOCK_TIME' ( N | 'UNBOUNDED' ) )*

LockOption ::= ( 'ACCOUNT' 'LOCK' | 'ACCOUNT' 'UNLOCK' )?

AttributeOption ::= ( 'COMMENT' CommentString | 'ATTRIBUTE' AttributeString )?

ResourceGroupNameOption::= ( 'RESOURCE' 'GROUP' Identifier)?

RequireClauseOpt ::= ('REQUIRE' ('NONE' | 'SSL' | 'X509' | RequireListElement ('AND'? RequireListElement)*))?

RequireListElement ::= 'ISSUER' Issuer | 'SUBJECT' Subject | 'CIPHER' Cipher | 'SAN' SAN | 'TOKEN_ISSUER' TokenIssuer

示例

mysql> CREATE USER 'newuser' IDENTIFIED BY 'newuserpassword';
Query OK, 1 row affected (0.01 sec)

mysql> SHOW CREATE USER 'newuser';
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| CREATE USER for newuser@%                                                                                                                                            |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| CREATE USER 'newuser'@'%' IDENTIFIED WITH 'mysql_native_password' AS '*5806E04BBEE79E1899964C6A04D68BCA69B1A879' REQUIRE NONE PASSWORD EXPIRE DEFAULT ACCOUNT UNLOCK |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

修改基本用户信息

更改用户 newuser 的密码：

mysql> ALTER USER 'newuser' IDENTIFIED BY 'newnewpassword';
Query OK, 0 rows affected (0.02 sec)

mysql> SHOW CREATE USER 'newuser';
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| CREATE USER for newuser@%                                                                                                                                            |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| CREATE USER 'newuser'@'%' IDENTIFIED WITH 'mysql_native_password' AS '*FB8A1EA1353E8775CA836233E367FBDFCB37BE73' REQUIRE NONE PASSWORD EXPIRE DEFAULT ACCOUNT UNLOCK |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

锁定用户 newuser：

ALTER USER 'newuser' ACCOUNT LOCK;

Query OK, 0 rows affected (0.02 sec)

修改 newuser 的属性：

ALTER USER 'newuser' ATTRIBUTE '{"newAttr": "value", "deprecatedAttr": null}';
SELECT * FROM information_schema.user_attributes;

+-----------+------+--------------------------+
| USER      | HOST | ATTRIBUTE                |
+-----------+------+--------------------------+
| newuser   | %    | {"newAttr": "value"}     |
+-----------+------+--------------------------+
1 rows in set (0.00 sec)

使用 ALTER USER ... COMMENT 修改 newuser 的备注：

ALTER USER 'newuser' COMMENT 'Here is the comment';
SELECT * FROM information_schema.user_attributes;

+-----------+------+--------------------------------------------------------+
| USER      | HOST | ATTRIBUTE                                              |
+-----------+------+--------------------------------------------------------+
| newuser   | %    | {"comment": "Here is the comment", "newAttr": "value"} |
+-----------+------+--------------------------------------------------------+
1 rows in set (0.00 sec)

使用 ALTER USER ... ATTRIBUTE 移除 newuser 的备注：

ALTER USER 'newuser' ATTRIBUTE '{"comment": null}';
SELECT * FROM information_schema.user_attributes;

+-----------+------+---------------------------+
| USER      | HOST | ATTRIBUTE                 |
+-----------+------+---------------------------+
| newuser   | %    | {"newAttr": "value"}      |
+-----------+------+---------------------------+
1 rows in set (0.00 sec)

通过 ALTER USER ... PASSWORD EXPIRE NEVER 改变 newuser 的密码自动过期策略为永不过期：

ALTER USER 'newuser' PASSWORD EXPIRE NEVER;

Query OK, 0 rows affected (0.02 sec)

通过 ALTER USER ... PASSWORD REUSE INTERVAL ... DAY 设置 newuser 的密码重用策略，不允许在过去 90 天内使用相同密码：

ALTER USER 'newuser' PASSWORD REUSE INTERVAL 90 DAY;

Query OK, 0 rows affected (0.02 sec)

修改用户绑定的资源组

使用 ALTER USER ... RESOURCE GROUP 将用户 newuser 的资源组修改为 rg1。

ALTER USER 'newuser' RESOURCE GROUP rg1;

Query OK, 0 rows affected (0.02 sec)

查看当前用户绑定的资源组：

SELECT USER, JSON_EXTRACT(User_attributes, "$.resource_group") FROM mysql.user WHERE user = "newuser";

+---------+---------------------------------------------------+
| USER    | JSON_EXTRACT(User_attributes, "$.resource_group") |
+---------+---------------------------------------------------+
| newuser | "rg1"                                             |
+---------+---------------------------------------------------+
1 row in set (0.02 sec)

取消用户的资源组绑定，即将用户绑定到 default 资源组。

ALTER USER 'newuser' RESOURCE GROUP `default`;
SELECT USER, JSON_EXTRACT(User_attributes, "$.resource_group") FROM mysql.user WHERE user = "newuser";

+---------+---------------------------------------------------+
| USER    | JSON_EXTRACT(User_attributes, "$.resource_group") |
+---------+---------------------------------------------------+
| newuser | "default"                                         |
+---------+---------------------------------------------------+
1 row in set (0.02 sec)

相关链接

• CREATE USER
• DROP USER
• SHOW CREATE USER