這個聯盟爲什麼不給我兩列？

Question

我想要連接的輸出中有兩列。我只得到一個，storeID。 StoreComponentID不在那裏。

Answer 1

如果你希望兩個欄需要聲明的兩列

SELECT column1, NULL as column2 -- even when Table1 doesnt have column2 
FROM Table1 
UNION 
SELECT NULL as column1, column2 -- even when Table2 doesnt have column1 
FROM Table2 

現在如果你想通過側某種合併的一面。

WITH idA as (
    SELECT StoreComponentID, 
      ROW_NUMBER() OVER (ORDER BY StoreComponentID) as rn 
    FROM StoreComponent 
), idB as (
    SELECT StoreID 
      ROW_NUMBER() OVER (ORDER BY StoreID) as rn 
    FROM Store 
) 
SELECT idA.StoreComponentID, 
     idB.StoreID 
FROM idA 
FULL JOIN idB 
    ON idA.rn = idB.rn 

Answer 2

我想出了一個簡單的解決方案：

select S.storeid as sID, SC.storecomponentid as SCID from tstore as S, tstorecomponent as SC