SQL服务器 - 查询帮助

Question

HI（通过与具有MAX组），

我在与一个查询一个巨大的问题，这是我在我的表中的数据：

entityId    groupId    groupDepth 
-------------------- -------------------- ----------- 
NULL     1090     0 
56     1090     1 
222     1090     1 
226     1090     1 
227     1090     1 
228     1090     1 
234     1090     1 
248     1090     2 
249     1090     2 
250     1090     2 
251     1090     2 
252     1090     1 
256     1090     1 
261     1090     1 
288     1090     1 
294     1090     1 
300     1090     1 
4691     1090     1 
4694     1090     1 
4697     1090     1 

所以我想要做的是在给定entityId和groupId时获得groupDepth最高的行。示例结果：

input: entityId = 294, groupId = 1090 
entityId    groupId    groupDepth 
-------------------- -------------------- ----------- 
294     1090     1 


input: entityId = 113, groupId = 1090 
entityId    groupId    groupDepth 
-------------------- -------------------- ----------- 
NULL     1090     0 

我在想是这样的：

SELECT * FROM [dbo].[EntityGroup] a 
WHERE EXISTS 
(
    SELECT groupId 
    FROM  [dbo].[EntityGroup] b 
    WHERE  
       (b.entityId is null or b.entityId = 294) AND 
       b.groupId = a.groupId 
    GROUP BY b.groupId 
    HAVING a.groupDepth = max(b.groupDepth) and 
       a.entityId = b.entityId 
) 

任何帮助将不胜感激！

Answer 1

SELECT entityID, groupId, groupDepth 
FROM EntityGroup t 
WHERE groupDepth = (SELECT MAX(groupDepth) FROM EntityGroup e WHERE COALESCE(e.entityID,-1) = COALESCE(t.entityId,-1) AND e.groupId = t.groupID) 
GROUP BY entityID, groupId, groupDepth 

如果我正确

编辑

SELECT entityID, groupId, groupDepth 
FROM EntityGroup t 
WHERE groupDepth = (SELECT MAX(groupDepth) FROM @Temp e WHERE e.entityID = t.entityId AND e.groupId = t.groupID) 
GROUP BY entityID, groupId, groupDepth 
UNION 
SELECT entityID, groupId, groupDepth 
FROM EntityGroup t 
WHERE groupDepth = (SELECT MAX(groupDepth) FROM @Temp e WHERE e.groupId = t.groupID AND e.entityId IS NULL) AND t.entityId IS NULL 
GROUP BY entityID,groupId, groupDepth 

Answer 2

这个怎么理解，你应该工作？

DECLARE @entityId INT = 294 
DECLARE @groupId INT = 1090 

SELECT TOP 1 entityId, groupid, Max(groupDepth) AS groupDepth 
FROM EntityGroup 
WHERE (entityId is null OR entityId = @entityId) 
AND groupId = @groupId 
GROUP BY entityId, groupId 
order by entityId desc 

编辑：更新SQL通过ENTITYID以降序排列，并采取第一个会给出正确的答案指定的情况下