如何合併兩個SQL SELECT

Question

我想合併兩個SQL從一個表

查詢1選擇

SELECT ShoppingLike.WhichId 
FROM ShoppingLike 
WHERE (ShoppingLike.ShoppingScoreTypeId = 2) AND (ShoppingLike.UserId = 189) 

代替75查詢1如何我應該使用查詢2的結果嗎？

Answer 1

可能帶有子選擇查詢？

SELECT UserId 
FROM ShoppingLike 
WHERE WhichId IN (
    SELECT WhichId 
    FROM ShoppingLike 
    WHERE (ShoppingScoreTypeId = 2) AND (UserId = 189) 
) 

儘管這將始終產生與UserId 189作爲結果行，在這種情況下，查詢可以簡單地這樣寫的：

SELECT UserId 
FROM ShoppingLike 
WHERE (ShoppingScoreTypeId = 2) AND (UserId = 189) 

這將返回一個排的每個記錄與ShoppingScoreTypeId = 2 UserId 189.

Answer 2

SELECT  UserId 
FROM   ShoppingLike 
WHERE  (ShoppingScoreTypeId = 2) 
AND WhichId = (
SELECT  top 1 ShoppingLike.WhichId 
FROM   ShoppingLike 
WHERE  (ShoppingLike.ShoppingScoreTypeId = 2) AND (ShoppingLike.UserId = 189) 
)