1

我在协作表中创建了下面的视图

CREATE VIEW contents(
  id,
  title
)
AS
select 
   mytable.id as id,
   mytable.title as title
from mytable 
where mytable.owner = substring_index(user(), '@', 1);

有没有办法像select, insert, update, deletewhere 子句一样检测视图内部的当前状态？

我希望像下面这样，不知道如何在 mysql/mariadb 中产生等价物

/* during select statement user can see all available data*/
if state == 'select' then
    where 1 = 1 /* can see all data */
else
/* if state is update or delete user is allowed to modify or delete data which for which he/she is owner*/
    where mytable.owner = substring_index(user(), '@', 1);
endif

这是我的示例数据

MariaDB [test]> select * from mytable;
+----+-------------------+-------+
| id | title             | owner |
+----+-------------------+-------+
|  1 | created by root   | root  |
|  4 | created by helen  | helen |
|  6 | created by helen1 | helen |
|  7 | 123               | lina |
+----+-------------------+-------+

用户 helen 和 linaSELECT, INSERT, UPDATE, DELETE对内容视图有授权

  • 另外用户helen是普通用户如何授予创建 new_database 的权限，并继承 helen 在 new_database 中创建的任何新表的权限？我不想创建 helen 作为管理员。用户 helen 应该能够在她创建的数据库中创建任意数量的数据库和表。这是否可能？
   new_database
         table1
         table2
         .....
         .....
         tableN
4

1 回答 1

2

由于检查约束不能使用user. 您可以使用 TRIGGERS 来强制执行fiddle等约束：

插入：

CREATE TRIGGER enforce_insert
BEFORE
INSERT ON mytable
FOR EACH ROW
  IF NEW.owner != substring_index(user(), '@', 1) THEN
    SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'conflict of owner on insert';
  END IF

更新：

CREATE TRIGGER enforce_update
BEFORE
UPDATE ON mytable
FOR EACH ROW
  IF OLD.owner != substring_index(user(), '@', 1)
     OR NEW.owner != substring_index(user(), '@', 1) THEN
    SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'conflict of owner on update';
  END IF

删除：

CREATE TRIGGER enforce_delete
BEFORE
DELETE ON mytable
FOR EACH ROW
  IF OLD.owner != substring_index(user(), '@', 1) THEN
    SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'conflict of owner on delete';
  END IF

然而，通常它建议应用程序强制执行数据结构的示意图。

参考：触发手册

于 2021-07-05T00:03:07.237 回答