SQL：比较两个表

Question

嗨，我有这种情况下，我在这里。

我有两个表格A和表格B，它们有一个共同的主键（panelist_id），每个panelist_id都有很多的entity_id。

我想检查是否为每个panelist_id和相同的entity_ids都存在于表中或没有。

注：有很多panelist_id的和每个panelist_ids有很多entity_ids ..

请帮助我。

Answer 1

Select A.panelist_id from tableA as A inner join tableB as B 
on A.panelist_id=B.panelist_id 
GROUP BY A.panelist_id 
HAVING COUNT(DISTINCT A.entity_id)=COUNT(DISTINCT B.entity_id) 

Answer 2

要选择panelist_id/ENTITY_ID元组，其仅在表中的一个可用的，你试试这样做：

select panelist_id, entity_id from 
(
    select panelist_id, entity_id from a 
    union all 
    select panelist_id, entity_id from b 
) 
group by panelist_id, entity_id 
having count(*) = 1; 

Answer 3

我不能工作了，你问什么，如果你只是想知道每个ENTITY_ID/Panelist_ID元组，如果它存在于一个或两个表，那么这将工作：

SELECT Panelist_ID, 
     Entity_ID, 
     CASE WHEN COUNT(A) > 0 AND COUNT(B) > 0 THEN 'Both Tables' 
      WHEN COUNT(B) = 0 THEN 'Table A' 
      WHEN COUNT(A) = 0 THEN 'Table B' 
     END AS Status 
FROM ( SELECT Panelist_ID, Entity_ID, 1 AS A, NULL AS B 
      FROM A 
      UNION ALL 
      SELECT Panelist_ID, Entity_ID, NULL AS A, 1 AS B 
      FROM B 
     ) T 
GROUP BY Panelist_ID, Entity_ID; 

如果你想知道哪里panelist_IDs每个表中的元组是在S AME，没有元组存在一个表不存在于另一方案则需要使用：

SELECT * 
FROM A 
     FULL JOIN B 
      ON A.Panelist_ID = B.Panelist_ID 
      AND A.Entity_ID = B.Entity_ID 
WHERE A.Entity_ID IS NOT NULL 
AND  B.Entity_ID IS NOT NULL; 

或者，如果你想知道的是存在于一个表中的元组，而不是其他你能用途：

SELECT * 
FROM A 
     FULL JOIN B 
      ON A.Panelist_ID = B.Panelist_ID 
      AND A.Entity_ID = B.Entity_ID 
WHERE A.Entity_ID IS NULL 
OR  B.Entity_ID IS NULL; 

编辑

基于对于只需要来验证一个临时表是一样的永久表，你可以使用EXISTS评论：

SELECT * 
FROM PermanentTable p 
WHERE NOT EXISTS 
     ( SELECT 1 
      FROM TempTable t 
      WHERE p.Panelist_ID = t.Panelist_ID 
      AND  p.Entity_ID = t.Entity_ID 
      ... More conditions to help find if entries are missing from temp table 
     )