สอบถามการใช้ Triggers ms sql server สำหรับบันทึกข้อมูล

ALTER TRIGGER [dbo].[Create_Component_Demand] 
   ON [dbo].[tblFinished_Goods]
   AFTER INSERT
AS 
BEGIN
	-- SET NOCOUNT ON added to prevent extra result sets from
	-- interfering with SELECT statements.
	SET NOCOUNT ON;

	
	IF EXISTS(SELECT * FROM INSERTED)
	BEGIN

		INSERT INTO tblPlan_Component_Demand
		(Pro_Ord,Mat_no,Pro_qty,Comp_no,Comp_qty)
		SELECT
		Pro_Ord,
		Mat_no,
		Pro_qty,
		(SELECT dbo.tblBOM.Comp_no
			FROM dbo.tblBOM INNER JOIN
			dbo.tblFinished_Goods 
			ON dbo.tblBOM.Mat_no = dbo.tblFinished_Goods.Mat_no
			WHERE (dbo.tblFinished_Goods.Pro_Ord 
			IN (SELECT Pro_Ord FROM INSERTED)) 
			AND (dbo.tblFinished_Goods.Mat_no 
			IN (SELECT Mat_no FROM INSERTED))),
		(SELECT dbo.tblBOM.Comp_qty
			FROM dbo.tblBOM INNER JOIN
			dbo.tblFinished_Goods 
			ON dbo.tblBOM.Mat_no = dbo.tblFinished_Goods.Mat_no
			WHERE (dbo.tblFinished_Goods.Pro_Ord 
			IN (SELECT Pro_Ord FROM INSERTED)) 
			AND (dbo.tblFinished_Goods.Mat_no 
			IN (SELECT Mat_no FROM INSERTED))
			AND (dbo.tblBOM.Comp_no 
			IN (SELECT dbo.tblBOM.Comp_no
				FROM dbo.tblBOM INNER JOIN
				dbo.tblFinished_Goods 
				ON dbo.tblBOM.Mat_no = dbo.tblFinished_Goods.Mat_no
				WHERE (dbo.tblFinished_Goods.Pro_Ord 
				IN (SELECT Pro_Ord FROM INSERTED)) 
				AND (dbo.tblFinished_Goods.Mat_no 
				IN (SELECT Mat_no FROM INSERTED)))))
		FROM INSERTED

	END
	

END