Hi,

I have a table with a primary key that is 3 columns.  I want to create a trigger (on update and on insert) on this table that updates a particular column on this table.  I've done this successfully for tables with a 1 column primary key .... but I don't think the same logic will apply.

Below is a simplified version of my table and the syntax for my trigger.  My problem is that when I do a batch insert (I insert 100 rows with the same PCode but different SPIDs), I'm afraid that on the insert of each row - it updates the column for all 100 each time.  So when it inserts the last row, it will update all the rows with the timestamp of when the last one was inserted.  Is my understanding correct?  Am I making a mountain out of a molehill?  I'm concerned that as data grows and as our batch inserts become larger .... that we will take a performance hit.  

CREATE TABLE [dbo].[Apple](
      [PCode] [nvarchar](50) NOT NULL,
      [SPID] [int] NOT NULL,
      [Month] [datetime] NOT NULL,

      [LastUpdatedTimeStamp] [datetime] NULL,
      [LastUpdatedBy] [nvarchar](50) NULL,
 CONSTRAINT [PK_Apple] PRIMARY KEY CLUSTERED
(
      [PCode] ASC,
      [SPID] ASC,
      [Month] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]


Create TRIGGER [dbo].[t_UpdInsApple] ON [dbo].[Apple]    FOR UPDATE,INSERT
AS
BEGIN
      SET NOCOUNT ON;
        BEGIN
            UPDATE  dbo.Apple
            SET     LastUpdatedTimeStamp = GETDATE(), LastUpdatedBy=SYSTEM_USER
            WHERE   pcode IN ( SELECT   pcode  FROM  inserted )
       END

END