Question

大家好我想更新父表的状态取决于子记录。

条件是。

具有字段Isclosed的子记录。

如果所有子记录Isclosed=1则父记录状态= 1
如果某些子记录Isclosed=1，则父记录状态= 2
其他父记录状态= 3

我试过这个：

update Parent set Status=1
where id in(
select ParentID from Child where
Isclosed=1  
 group by ParentID having count(id)=(select count(id)from Child where Parent.id=ParentID))

但它只满足一个条件。

Answer 1

您可以使用CTE获取COUNT个Child条记录IsClosed = 1以及COUNT条Child条记录每Parent。然后使用CTE到UPDATE Parent记录状态的结果：

WITH Cte AS(
    SELECT
        p.Id,
        ClosedCount = SUM(CASE WHEN c.IsClosed = 1 THEN 1 ELSE 0 END),
        TotalCount = COUNT(*)
    FROM Parent p
    INNER JOIN Child c
        ON c.ParentId = p.Id
    GROUP BY p.Id
)
UPDATE p
    SET p.Status =
        CASE
            WHEN c.ClosedCount = c.TotalCount THEN 1
            WHEN c.ClosedCount = 0 THEN 3
            ELSE 2          
        END
FROM Parent p
INNER JOIN Cte c
    ON c.Id = p.Id

SQL Fiddle

Answer 2

试试这个简单的查询，可能会帮到你

UPDATE  P
SET P.status = (CASE WHEN MaxIsclosed = MinIsclosed AND MaxIsclosed > 0 THEN 1
                    WHEN MaxIsclosed > 0 THEN 2 ELSE 3 END)
FROM    Parent P
LEFT OUTER JOIN (SELECT PARENTID,MAX(Isclosed) AS MaxIsclosed,MIN(Isclosed) AS MinIsclosed 
    FROM CHILD  GROUP BY PARENTID)  C ON P.PARENTID = C.PARENTID

Answer 3

只需完成以下查询。

UPDATE [Parent]
 SET    [Status]  = CASE WHEN EXISTS (  SELECT  [ParentID]
                                        FROM    [Child]
                                        WHERE   [ParentID] = [Parent].[id]
                                        GROUP BY [ParentID]
                                        HAVING SUM([Isclosed]) = COUNT([ParentID])
                                    )
                        THEN    1
                        WHEN EXISTS (   SELECT  [ParentID]
                                        FROM    [Child]
                                        WHERE   [ParentID] = [Parent].[id]
                                        GROUP BY [ParentID]
                                        HAVING SUM([Isclosed]) = 0
                                    )
                        THEN    3
                        ELSE    2
                    END

如果需要，您可以将[已关闭] CAST为。

根据子记录更新父表

3 个答案: