SQL Trigger on Insert, Delete, Updated

I have the following trigger

 ALTER TRIGGER [dbo].[RefreshProject]
   ON  [dbo].[Project] 
   AFTER INSERT,DELETE,UPDAT开发者_如何学CE
AS 
BEGIN
SET NOCOUNT ON
DECLARE @percentage decimal(18,2)
DECLARE @ProjectID int
DECLARE @TASKID int

IF EXISTS(SELECT * FROM Inserted)
    BEGIN
        SELECT @ProjectID = Inserted.ProjectID, @TASKID = ISNULL(Inserted.TASKID,-1) from Inserted join Project on Inserted.ScheduleID = Project.ScheduleID
    END

IF EXISTS(SELECT * FROM Deleted)
    BEGIN
        SELECT @ProjectID = Deleted.ProjectID,@TASKID = ISNULL(Deleted.TASKID,-1) from Deleted join Project on Deleted.ScheduleID = Project.ScheduleID
    END

    BEGIN
         SET @percentage = (SELECT percentage from Project where ProjectID = @ProjectID)
         EXEC LoadSummary @percentage,@ProjectID, @TASKID
    END
END

For Inserts and updates I am able to get the ProjectID of the modified object, however when an item is deleted, I can not get the ProjectID or TaskID... Any Idea what I'm doing wrong?

The problem is that your trigger is an AFTER trigger, which means that the row has already been deleted from the Project table by the time the trigger is fired. So, you can't join the deleted view to Project, because the corresponding row won't exist. You will need to assign the variables you want directly from the deleted view.

Also, as Mitch's note mentions above, you may want to use a cursor to iterate over all rows in the inserted/deleted views if multiple rows can be updated at a time. Alternatively, you could raise an error at the beginning of your trigger if @@ROWCOUNT is greater than one, to prevent multiple row updates from causing your trigger to misbehave.