觸發器內的案例陳述

Question

create trigger Insert_emp on dbo.emp
after insert
as
begin

declare @tablename varchar(50)
declare @rdatetime varchar(20)
declare @month int

set @rdatetime = (select Bdate from inserted)
set @month = (select datepart(mm,@rdatetime))
case when @month = 2 then set @tablename = 'FEP_EMP' end
print @tablename 
end

觸發器將在將記錄插入emp表后執行。它將選擇插入的日期。將從該日期開始計算月份。我想要設置表名的值。

Answer 1

SQL Server中的CASE僅可用於獲取標量值- 不能用於確定執行哪個代碼塊或語句。 要處理條件代碼執行，請使用常規的IF / ELSE語句。

將觸發器更改為類似以下內容：

create trigger Insert_emp on dbo.emp
after insert
as
begin

   declare @tablename varchar(50)
   declare @rdatetime varchar(20)
   declare @month int

   set @rdatetime = (select Bdate from inserted)
   set @month = (select datepart(mm,@rdatetime))

   IF @month = 2 
      set @tablename = 'FEP_EMP' 

   print @tablename 
end