加入操作不起作用

Question

我有三张桌子tbA和tbB

TBA

• tbAId
• tbAName

TBB

• tbBId
• tbBName

TBC

• tbCId
• tbAId
• tbBId

现在我必须获取分配给tbA的所有BName

我试过像

SELECT   
L.tbBId L.tbBName FROM tbB L
JOIN
tbC P ON P.tbAId = @AId;

请帮帮我!!!

Answer 1

select tbAId,tbAName,tbBName
from tbA join tbC
on tbA.tbAId=tbC.tbAId
join tbB
on tbB.tbBId=tbC.tbBId
WHERE  P.tbAId = @AId

Answer 2

需要更改的更正

1。您没有用逗号分隔两列

L.tbBId L.tbBName

2。您尚未在查询中考虑过表格tbA＆amp;您将tbAId放入查询

以下是更改后的查询。我想这会对你有帮助

SELECT 
    L.tbBId,
    L.tbBName
FROM
    tbB L
INNER JOIN 
    tbC P ON P.tbBId = L.tbBId
INNER JOIN 
    tbA A ON P.tbAId = A.tbAId
WHERE  
    P.tbAId = @AId; 

Answer 3

试试这个..

SELECT L.tbBId,
       L.tbBName
FROM   tbB L
       JOIN tbC P
         ON P.tbBId = L.tbBId
       JOIN tbA A
         ON P.tbAId = A.tbAId
WHERE  P.tbAId = @AId;