如何從我知道第二張桌子的ID的第一張桌子

Question

我需要獲取兩個表，這是表結構

表A

• 用戶身份
• 用戶名
• 狀態
• 簡介碼

表B

• 簡介碼
• 用戶身份

我想獲取表a的數據並在tblA.IntroCode = tblB.IntroCode上與表b聯接，然后獲取tblB.userID的用戶名。 我該如何加入？

我嘗試了一半，卡在中間，請幫忙。 謝謝您的回復

Answer 1

這只是一個簡單的連接。

SELECT  a.*, b.*    -- select your desired columns here
FROM    tableA a
        INNER JOIN tableB b
            ON a.IntroCode = b.IntroCode
WHERE   b.userid = valueHere

更新1

SELECT  a.UserID, 
        a.`Username` OrigUserName,
        a.`Status`,
        c.`Username` IntroUserName
FROM    tableA a
        INNER JOIN tableB b
            ON a.IntroCode = b.IntroCode
        INNER JOIN tableA c
            ON b.userID = c.userID
-- WHERE b.UserID = valueHere       -- extra condition here

Answer 2

SELECT column_name(s)
FROM TableA
LEFT JOIN TableB
ON TableA.UserID=TableB.UserID

Answer 3

SELECT B.userID from TableA A
LEFT JOIN TableB B on A.IntroCode=B.IntroCode

Answer 4

select a.*,b.IntroCode  from TableA a left join TableB b
on a.IntroCode = b.IntroCode 

Answer 5

您必須為具有相同名稱的列賦予唯一值：

SELECT  a.UserID as uid_a, b.UserID as uid_b
FROM    tableA a
INNER JOIN tableB b ON a.IntroCode = b.IntroCode
WHERE   b.UserID = 1

Answer 6

使用此查詢。

 SELECT TableA.Username FROM TableA JOIN TableB ON (TableA.IntroCode = TableB.IntroCode);

Answer 7

使用此查詢

SELECT  *  FROM tblA INNER JOIN tblB ON tblA.IntroCode = tblB.IntroCode where tblB.userid = value