SQL左连接查询的多个列

Question

我希望参加以下两个表

Table_1_CODE 

Code Desc 
LC01 Karachi 
LC02 Hyderabad 
DP01 Account 
DP02 Marketing 
SH01 Night 
SH02 Day 


Table_2_DETAILS 

Col_1 Col_2 Col_3 Col_4 
Mumtaz LC01 DP02 SH01 
Sajid LC02 DP01 SH02 
Imtiaz LC01 DP02 SH02 

我期待的输出为

Name Loc  Dept  Shift 
Mumtaz Karachi Marketing Night 
Sajid Hyderabad Account Day 
Imtiaz Karachi Marketing Day 

我要做到这一点使用SQL

Answer 1

请尝试以下查询：

SELECT col_1, t11.description, t12.description, t13.description 
FROM Table_2_DETAILS t2 INNER JOIN Table_1_Code t11 
ON t11.code = t2.Col_2 
INNER JOIN Table_1_Code t12 
ON t12.code = t2.col_3 
INNER JOIN Table_1_Code t13 
ON t13.code = t2.col_4; 

我还没有运行查询，所以如果有任何问题，请评论。

Answer 2

这就是你想要的。您必须在不同的列上多次连接表1。

SELECT Col_1 AS 'Name',a.[Desc] AS 'Loc',b.[Desc] AS 'Dept',c.[Desc] AS 
'Shift' 
FROM Table_2 
    JOIN Table_1 a ON Table_2.Col_2 = a.Code 
    JOIN Table_1 b ON Table_2.Col_3 = b.Code 
    JOIN Table_1 c ON Table_2.Col_4 = c.Code 

ORDER BY c.[Desc] DESC 
GO