小编Abh*_*bhi的帖子

我运行了一份报告，在该报告中，我遇到了一种情况，即基于基本上是键或 Id 的列值，我需要从映射 Id 表中获取相应的值。像下面这样：

    SELECT
     (case when [column1='A'] then (select value from Table1) 
           when [column1='B'] then (select value from Table2) 
           when [column1='C'] then (select value from Table3)

           and so on uptil 35 more 'when' conditions ...

  ELSE column1 end) Value 
from Table1

更确切地说：

SELECT 
(case when [A.column1='1'] 
then (select value from B where B.clientId=100 and A.column1=B.Id) 
when [A.column1='2'] 
then (select value from C where C.clientId=100 and A.column1=C.Id) 
when [A.column1='3'] 
then (select value from D where D.clientId=100 and A.column1=D.Id) 
... …