基于案例的联盟

Question

有没有一种方法可以基于像这样的 Case 语句来创建联合：

Case
    When @var = 1 Then Select * from TableA Union Select * From TableB
    When @Var = 2 Then Select * From TableC Union Select * From TableD
    When @Var = 3 Then Select * From TableA Union Select * From TableE
    ...
End

我可以处理的确切信息和从中获取的表格我只是好奇这个概念在 SQL Server 2012 上是否可行。

因此，根据该评论，这是否是正确的语法：

IF @var = 1
    Select * from TableA Union Select * From TableB
ELSE
IF @Var = 2
    Select * From TableC Union Select * From TableD
Else
IF @Var = 3
    Select * From TableA Union Select * From TableE
Else
...

Answer 1

因此，根据@Lamak 的评论，我能够使用以下方法获得我想要的结果：

IF @var = 1
    Select * from TableA Union Select * From TableB
ELSE
IF @Var = 2
    Select * From TableC Union Select * From TableD
Else
IF @Var = 3
    Select * From TableA Union Select * From TableE
Else
...

基于案例的联盟

Union based on Case

union

case

sql-server-2012