更新插入MSSql觸發器（Updatecounter）

Question

我有一個名爲Table1的表，其中有兩個字段Systemname和Updatecount。 帶有Systemname「SAP」的每個插入應該將Updatecount設置爲1（初始值）。 如果字段系統名稱使用定義值「SAP」獲取更新，則字段更新計數應該增加1.

如何定義觸發器？

Answer 1

create trigger tr on Table1 for insert,update 
as 
begin 
    if update(Systemname) 
     update Table1 
      set UpdateCount = (case when not exists(select * from deleted) then 1 else UpdateCount + 1 end) 
     from Table1 
     inner join inserted on Table1.[<YourPKField>] = inserted.[<YourPKField>] 
     where inserted.Systemname = 'SAP' 
end 
GO 

Answer 2

有上觸發一個很好的文章在這裏：

http://www.codeproject.com/Articles/38808/Overview-of-SQL-Server-database-Triggers

您需要創建：

CREATE TRIGGER [TRIGGER_ALTER_COUNT] ON [dbo].[tblTriggerExample] 
FOR INSERT, UPDATE 
AS 
BEGIN 
DECLARE @Var INT 
SELECT @Var = COUNT(*) FROM INSERTED 
UPDATE [dbo].[tblTriggerExample] SET AlterCount = AlterCount + Var 
      ,LastUpdate = GETDATE() 
    WHERE TransactionID = @TransID 
SELECT @Var = COUNT(*) FROM UPDATED WHERE SystemNAme = 'Var' 
UPDATE [dbo].[tblTriggerExample] SET AlterCount = AlterCount + @Var 
      ,LastUpdate = GETDATE() 
    WHERE TransactionID = @TransID 
END