Question

我有3个表来管理用户的权利

Employee
+-----------+------+
|EmployeeID | Name |
+-----------+------+
|1          |Tim   |
|2          |Tom   |
+-----------+------+

Right
+-----------+------+
|RightID    |Name  |
+-----------+------+
|1          |Read  |
|2          |Write |
|3          |Change|
+-----------+------+

EmployeeRight
+-----------+--------+
|EmplyeeID  | RightID|
+-----------+--------+
|1          |1       |
|1          |2       |
|2          |1       |
+-----------+--------+

现在我需要为所有用户提供正确的＆＃34;更改＆＃34;哪个有权＆＃34;写＆＃34;。但已经拥有该权利的用户不应该两次获得它。

我目前的尝试不起作用：

INSERT INTO EmployeeRight 
(SELECT '3', EmployeeID FROM EmployeeRight WHERE RightID = 2 AND RightID !=3)

Answer 1

使用以下脚本。

INSERT INTO Employee-Right
SELECT EmployeeID,3
FROM Employyee E
WHERE EXISTS (SELECT 1
FROM Employee-Right ER WHERE E.EmployeeID=ER.EmployeeID AND ER.Right=2 )
  AND NOT EXISTS (SELECT 1
FROM Employee-Right ER WHERE E.EmployeeID=ER.EmployeeID AND ER.Right=3 )

或者您可以直接从Employee-right表

查询

INSERT INTO Employee-Right
SELECT DISTINCT EmployeeID,3
FROM Employee-Right ER
WHERE ER.Right=2 
  AND NOT EXISTS (SELECT 1
FROM Employee-Right ER1 WHERE ER.EmployeeID=ER1.EmployeeID AND ER.Right=3 )

Answer 2

在单行中RightID不能同时为2和<>2，您需要这样的查询：

INSERT INTO EmployeeRight 
SELECT EmployeeID, 3 
FROM EmployeeRight 
WHERE RightID = 2 -- existing right 2
  AND EmployeeID NOT IN
   (
     SELECT EmployeeID 
     FROM EmployeeRight 
     WHERE RightID = 3 -- but not those who already have right 3
   )

Answer 3

尝试以下查询

            INSERT INTO EmployeeRight      
            select E.EmployeeID,'3' as RightID from Employee E
            left join EmployeeRight ER on ER.EmplyeeID = E.EmployeeID
            left join Right r on r.RightID=ER.RightID
            where er.RightID = 2 and er.RightID != 3

SQL向关系表添加关系

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