用SQL查詢

Question

我有一個表稱爲事務

Transaction: 
    User_Id: int 
    Transaction_Type: int 
    Amount: int 

我多麼查詢沒有交易類型1.

SELECT * FROM Transaction WHERE Transaction_Type <> 1 Group By User_Id 

所有用戶彷彿回到所有用戶掙扎&他們的交易類型不= = 1.我需要所有缺少/沒有1類記錄的用戶。

Answer 1

這可以通過IN()子查詢

SELECT DISTINCT User_Id FROM Transaction 
WHERE User_Id NOT IN (SELECT DISTINCT User_Id FROM Transaction WHERE Transaction_Type = 1) 

或者用NOT EXISTS

SELECT 
    DISTINCT User_Id 
FROM Transaction t 
WHERE 
    NOT EXISTS (SELECT User_Id FROM Transaction tn WHERE Transaction_Type = 1) 
    AND t.User_Id = tn.User_Id 

Answer 2

有可能這樣做的更優雅的方式，但這應該工作：

SELECT * FROM Transaction WHERE User_Id NOT IN (SELECT User_Id FROM Transaction WHERE Transaction_Type = 1) 

Answer 3

SELECT DISTINCT User_Id 
FROM Transaction 
WHERE Transaction_Id <> 1 
GROUP BY User_Id 

這得到它在每個User_Id至少有一個不屬於類型1的交易。如果您還想要沒有交易的交易，請添加OR Transaction_Id IS NULL至WHERE聲明。

Answer 4

SELECT * 
FROM (SELECT DISTINCT User_Id FROM Transaction) AS User 
LEFT JOIN Transaction ON Transaction.User_Id   = User.id 
        AND Transaction.Transaction_Id != 1 
WHERE Transaction.Transaction_Id IS NULL 
GROUP BY User.id 

Answer 5

例如

SELECT DISTINCT User_Id 
FROM [Transaction] 
EXCEPT 
SELECT User_Id 
FROM [Transaction] 
WHERE Transaction_Id = 1 

那如果你沒有爲用戶提供單獨的表的。如果你這樣做，那麼使用外連接。

我不會使用關鍵字（如Transaction）爲表/列名

Answer 6

我會用JOIN做到這一點建議。假設Users表：

SELECT u.* 
FROM Users u 
LEFT JOIN Transaction t 
ON t.User_ID = u.User_ID 
AND t.Transaction_Type = 1 
WHERE t.User_ID IS NULL 

這種方法避免了子查詢和DISTINCT。