TSQL：if語句選擇插入

Question

裏面我有這個結構的函數內部：

INSERT INTO @TheTable 
    SELECT DISTINCT 

     @Number AS Number, 

     @Name AS Name 

    FROM MYTABLE 
    WHERE id = @id 

我需要添加到這種結構的結果來執行其他功能的，我需要你的幫助，這樣做。

下面的@Name AS名，行我要補充的是這樣的

IF (dbo.anotherFunction(@id)==1) 
@NewVisitor AS NewVisitor 
ELSE 
@NewVisitor AS NoNewVisitor 

我怎樣才能轉化爲TSQL這個？

非常感謝！

Answer 1

猜測這是你想要的...

INSERT INTO @TheTable 
    SELECT DISTINCT 
     @Number AS Number, 
     @Name AS Name, 
     case when (dbo.anotherFunction(@id)=1) then @NewVisitor else null end as NewVisitor, 
     case when (dbo.anotherFunction(@id)<>1) then @NewVisitor else null end AS NoNewVisitor 
    FROM MYTABLE 
    WHERE id = @id 

Answer 2

IF語句不可用SELECT語句的內部。相反，你會想要使用CASE。

MSDN Documentation on CASE

Answer 3

這個問題沒有什麼意義，我（爲什麼所有的變量，有什麼事列呢？），但你可以這樣來做：

IF (dbo.anotherFunction(@id)==1) 
    INSERT INTO @TheTable 
    SELECT DISTINCT 
     @Number AS Number, 
     @Name AS Name, 
     @NewVisitor AS NewVisitor 
    FROM MYTABLE 
    WHERE id = @id 
ELSE 
    INSERT INTO @TheTable 
    SELECT DISTINCT 
     @Number AS Number, 
     @Name AS Name, 
     @NewVisitor AS NoNewVisitor 
    FROM MYTABLE 
    WHERE id = @id 

或者使用兩個CASE語句選擇NewVisitor和NoNewVisitor。