SQL：比較兩個表

Question

嗨，我有這種情況下，我在這裏。

我有兩個表格A和表格B，它們有一個共同的主鍵（panelist_id），每個panelist_id都有很多的entity_id。

我想檢查是否爲每個panelist_id和相同的entity_ids都存在於表中或沒有。

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

請幫助我。

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

要選擇panelist_id/ENTITY_ID元組，其僅在表中的一個可用的，你試試這樣做：

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，你問什麼，如果你只是想知道每個ENTITY_ID/Panelist_ID元組，如果它存在於一個或兩個表，那麼這將工作：

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; 

如果你想知道哪裏panelist_IDs每個表中的元組是在S AME，沒有元組存在一個表不存在於另一方案則需要使用：

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於一個表中的元組，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; 

編輯

基於對於只需要來驗證一個臨時表是一樣的永久表，你可以使用EXISTS評論：

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 
     )