如何在mysql中

取2個不同的表中的數據我有兩個表：如何在mysql中

Subscriber_detail 

SubscriberID | Merchant_ID 
23   | 24 

User_Detail 

User_ID | User_RegisteredID 

23  | 1001001 
24  | 1001002

需要從User_Login表中提取User_RegisteredID爲SubscriberID and Merchant_ID from Subscriber_Detail

來源

2013-05-03 user550076

爲什麼人們不要Google這些東西？ – Jared 2013-05-03 05:01:43

@Jared bcoz我們人們總是在這裏評論和迴應這些類型的問題;） – swapnesh 2013-05-03 05:02:23

@swapnesh肯定它已經在這裏回答了...... – Jared 2013-05-03 05:04:09

SELECT sub.User_RegisteredID AS SubscriberRegisteredID, 
     mer.User_RegisteredID AS MerchantRegisteredID 
FROM Subscriber_detail s 
     JOIN User_Detail sub on s.SubscriberID = sub.User_ID 
     JOIN User_Detail mer ON s.Merchant_ID = mer.User_ID

你需要加入兩個表和表User_Detail應連接兩次，因爲引用表Subscriber_detail中有兩列。

如果一列是NULLABLE，應該使用LEFT JOIN。

SELECT sub.User_RegisteredID AS SubscriberRegisteredID, 
     mer.User_RegisteredID AS MerchantRegisteredID 
FROM Subscriber_detail s 
     LEFT JOIN User_Detail sub on s.SubscriberID = sub.User_ID 
     LEFT JOIN User_Detail mer ON s.Merchant_ID = mer.User_ID

來源

2013-05-03 05:08:17

回答

相關問題