使用CASE和SELECT从另一个表使用CONVERT

Question

我正在使用SQL Server，我需要查询帮助。

这是情景：

我有2个表Roster和Customer。

PK [ID]存在于两个表中。

CREATE TABLE [dbo].[Tbl_Roster_Test](
    [CONCATENATE_NUMBER] [varchar](100) NOT NULL, 
    [CONCATENATE_NAME] [varchar](100) NULL, 
    [CUST_ID] [varchar](100) NULL, 
    [CUST_NAME] [varchar](100) NULL, 
    [ID] [varchar](100) NOT NULL, 
    [ID_NAME] [varchar](100) NULL, 
) ON [PRIMARY] 

CREATE TABLE [dbo].[Tbl_Customer_Test](
    [ID] [varchar](100) NOT NULL, 
    [CUST_ID_1] [varchar](100) NULL, 
    [CUST_ID_2] [varchar](100) NULL, 
) ON [PRIMARY] 

INSERT INTO [BOSSTest].[dbo].[Tbl_Roster_Test] 
([CONCATENATE_NUMBER],[CONCATENATE_NAME],[CUST_ID],[CUST_NAME],[ID],[ID_NAME]) 
SELECT 'US193085','UNIVERSITY OF ARIZONA','','','US193085','UNIVERSITY OF ARIZONA' 
UNION ALL 
SELECT 'US193085117933','UNIVERSITY OF ARIZ','117933','UNIVERSITY OF ARIZ','US193085','UNIVERSITY OF ARIZONA' 
UNION ALL 
SELECT 'US193085T22346','UNIVERSITY OF AZ','T22346','UNIVERSITY OF AZ','US193085','UNIVERSITY OF ARIZONA' 

INSERT into [BOSSTest].[dbo].[Tbl_Customer_Test] 
([ID],[CUST_ID_1],[CUST_ID_2]) 
SELECT 'US193085','117933','' 
UNION ALL 
SELECT 'US193085','T22346','' 
UNION ALL 
SELECT 'US193085','T22346','117933' 
UNION ALL 
SELECT 'US193085','','' 

逻辑...

In [Tbl_Roster_Test] 
IF [CUST_ID] = '' THEN [CONCATENATE_NAME] = [ID_Name] 
ELSE 
IF [CUST_ID] <> '' THEN [CONCATENATE_NAME] = [Cust_ID_Name] 

知道了这一点，现在我尝试使用[ID]使用上述逻辑来两个表链接。

如果有[CUST_ID]，然后选择[Cust_ID_Name]，如果没有则选择[ID_NAME]

有3种情况：

1. There is no data in [Cust_ID] 
2. There is data in [CUST_ID_1] 
3. There is no data in [CUST_ID_1] and There is data in [CUST_ID_2] 

当我执行此查询...

SELECT 
C.[ID] 
,C.[CUST_ID_1] 
,C.[CUST_ID_2] 
,(SELECT TOP 1 ISNULL([CONCATENATE_NAME],'') FROM BOSSTest.dbo.Tbl_Roster_Test R WHERE C.[ID] = R.[ID]) AS [Customer_Name] 

FROM [BOSSTest].[dbo].[Tbl_Customer_Test] C 

这就是我得到的。

+--------+------ -+---------+---------------------+ 
|  ID|CUST_ID_1|CUST_ID_2|  Customer_Name| 
+--------+------ -+---------+---------------------+ 
|US193085| 117933|   |UNIVERSITY OF ARIZONA| 
|US193085| T22346|   |UNIVERSITY OF ARIZONA| 
|US193085| T22346| 117933|UNIVERSITY OF ARIZONA| 
|US193085|   |   |UNIVERSITY OF ARIZONA| 
+--------+---------+---------+---------------------+ 

然后我试图使用子查询...

SELECT 
[ID] 
,[CUST_ID_1] 
,[CUST_ID_2] 
,CASE WHEN [CUST_ID_1] <> 
THEN (SELECT TOP 1 CONVERT(INT, CASE WHEN IsNumeric(CONVERT(VARCHAR(100),[CONCATENATE_NAME])) = 1 then CONVERT(VARCHAR(100),[CONCATENATE_NAME]) else 0 End) FROM BOSSTest.dbo.Tbl_Roster_Test R WHERE [CUST_ID_1] = R.[CUST_ID]) 
ELSE 0 END AS [Customer_Name] 

FROM (

    SELECT 
    C.[ID] 
    ,C.[CUST_ID_1] 
    ,C.[CUST_ID_2] 
    ,(SELECT TOP 1 ISNULL([CONCATENATE_NAME],'') FROM BOSSTest.dbo.Tbl_Roster_Test R WHERE C.[ID] = R.[ID]) AS [Customer_Name] 

    FROM [BOSSTest].[dbo].[Tbl_Customer_Test] C 

) AS TEST 

这是我所得到的。

+--------+------ -+---------+-------------+ 
|  ID|CUST_ID_1|CUST_ID_2|Customer_Name| 
+--------+------ -+---------+-------------+ 
|US193085| 117933|   |   NULL| 
|US193085| T22346|   |   0| 
|US193085| T22346| 117933|   0| 
|US193085|   |   |   0| 
+--------+---------+---------+-------------+ 

我以前CONVERT避免以下错误Syntax error converting the varchar value 'UNIVERSITY OF AZ' to a column of data type int.

但最后，这是我真正需要的。

+--------+------ -+---------+---------------------+ 
|  ID|CUST_ID_1|CUST_ID_2|  Customer_Name| 
+--------+------ -+---------+---------------------+ 
|US193085| 117933|   | UNIVERSITY OF ARIZ| 
|US193085| T22346|   |  UNIVERSITY OF AZ| 
|US193085| T22346| 117933|  UNIVERSITY OF AZ| 
|US193085|   |   |UNIVERSITY OF ARIZONA| 
+--------+---------+---------+---------------------+ 

任何关于如何使用3种情况运行此逻辑并充分利用CONVERT的建议。

由于提前， 路易斯

Answer 1

我认为这是在Tbl_Customer_Test插入条款的错误 - 你介意H17933，而不是117933？

如果是这样的一个情况，那么你必须写水木清华这样

SELECT CT.*,RT.CONCATENATE_NAME 
FROM [dbo].[Tbl_Customer_Test] CT 
left join [dbo].[Tbl_Roster_Test] RT 
on RT.CONCATENATE_NUMBER = 
CT.[ID] + isnull(nullif(ct.[CUST_ID_1],''), ct.[CUST_ID_2]) 

答案是

ID   CUST_ID_1 CUST_ID_2 CONCATENATE_NAME 
---------- ----------- ----------- --------------------- 
US193085 H17933     UNIVERSITY OF ARIZ 
US193085 T22346     UNIVERSITY OF AZ 
US193085 T22346  H17933  UNIVERSITY OF AZ 
US193085       UNIVERSITY OF ARIZONA 

UPD

由于补充意见（我们吃的第一个符号:)

SELECT CT.*,RT.CONCATENATE_NAME 
FROM [dbo].[Tbl_Customer_Test] CT 
join [dbo].[Tbl_Roster_Test] RT 
on RT.CONCATENATE_NUMBER like 
CT.[ID] + isnull(stuff(isnull(nullif(ct.[CUST_ID_1],''),ct[CUST_ID_2]),1,1,'_'),'')