SET DEFAULT ROLE

SET DEFAULT ROLE 语句默认设置将特定角色应用于用户。因此，用户不必执行 SET ROLE <rolename> 或 SET ROLE ALL 语句，也可以自动具有与角色相关联的权限。

语法图

SetDefaultRoleStmt:

SetDefaultRoleStmt

SetDefaultRoleOpt:

SetDefaultRoleOpt

RolenameList:

RolenameList

UsernameList:

UsernameList

示例

创建新角色 analyticsteam 和新用户 jennifer：

1. $ mysql -uroot

3. CREATE ROLE analyticsteam;
4. Query OK, 0 rows affected (0.02 sec)
5. GRANT SELECT ON test.* TO analyticsteam;
6. Query OK, 0 rows affected (0.02 sec)
7. CREATE USER jennifer;
8. Query OK, 0 rows affected (0.01 sec)
9. GRANT analyticsteam TO jennifer;
10. Query OK, 0 rows affected (0.01 sec)

需要注意的是，默认情况下，用户 jennifer 需要执行 SET ROLE analyticsteam 语句才能使用与角色相关联的权限：

1. $ mysql -ujennifer

3. SHOW GRANTS;
4. +---------------------------------------------+
5. | Grants for User                             |
6. +---------------------------------------------+
7. | GRANT USAGE ON *.* TO 'jennifer'@'%'        |
8. | GRANT 'analyticsteam'@'%' TO 'jennifer'@'%' |
9. +---------------------------------------------+
10. 2 rows in set (0.00 sec)

12. SHOW TABLES in test;
13. ERROR 1044 (42000): Access denied for user 'jennifer'@'%' to database 'test'
14. SET ROLE analyticsteam;
15. Query OK, 0 rows affected (0.00 sec)

17. SHOW GRANTS;
18. +---------------------------------------------+
19. | Grants for User                             |
20. +---------------------------------------------+
21. | GRANT USAGE ON *.* TO 'jennifer'@'%'        |
22. | GRANT Select ON test.* TO 'jennifer'@'%'    |
23. | GRANT 'analyticsteam'@'%' TO 'jennifer'@'%' |
24. +---------------------------------------------+
25. 3 rows in set (0.00 sec)

27. SHOW TABLES IN test;
28. +----------------+
29. | Tables_in_test |
30. +----------------+
31. | t1             |
32. +----------------+
33. 1 row in set (0.00 sec)

执行 SET DEFAULT ROLE 语句将用户 jennifer 与某一角色相关联，这样该用户无需执行 SET ROLE 语句就能拥有与角色相关联的权限。

1. $ mysql -uroot

3. SET DEFAULT ROLE analyticsteam TO jennifer;
4. Query OK, 0 rows affected (0.02 sec)

1. $ mysql -ujennifer

3. SHOW GRANTS;
4. +---------------------------------------------+
5. | Grants for User                             |
6. +---------------------------------------------+
7. | GRANT USAGE ON *.* TO 'jennifer'@'%'        |
8. | GRANT Select ON test.* TO 'jennifer'@'%'    |
9. | GRANT 'analyticsteam'@'%' TO 'jennifer'@'%' |
10. +---------------------------------------------+
11. 3 rows in set (0.00 sec)

13. SHOW TABLES IN test;
14. +----------------+
15. | Tables_in_test |
16. +----------------+
17. | t1             |
18. +----------------+
19. 1 row in set (0.00 sec)

SET DEFAULT ROLE 语句不会自动将相关角色授予 (GRANT) 用户。若尝试为 jennifer 尚未被授予的角色执行 SET DEFAULT ROLE 语句会导致以下错误：

1. SET DEFAULT ROLE analyticsteam TO jennifer;
2. ERROR 3530 (HY000): `analyticsteam`@`%` is is not granted to jennifer@%

MySQL 兼容性

SET DEFAULT ROLE 语句与 MySQL 8.0 的角色功能完全兼容。如发现任何兼容性差异，请在 GitHub 上提交 issue。

另请参阅