Thanks, I'll check it out.

now I just changed a computer. try to set up everything again on the new one, as my old laptop become sooo slow, hardly can do...

when you say identity, do you mean it is a primary key?

Dear SS, sorry for the delay to get back to you late. I just finished one exam on diffirent subject this morning, I had to concentrate on that.

now, I come...

Thanks SS!!!

I have also modified a bit and I will try it out later today.

Thanks kindly!:-)

Thanks very much :-), SS!

I really do not know what else I should do. I did read the article flolow your advice and posted the system script from my tables...

Sean,

I am quite new to SQL.

but at the begining, I have said, this is my study project, so, the tables are my real enviornment. there are three tables,

product table...

Thanks Sean ans SS Barry!

here is my

1) create tabel for PurchaseOrder system script;

2) insert into system script;

3) sample data from the actual PurchaseOrder table

1) --create table

USE [ProjectTesting]

GO

/****** Object:...

SS, do you know is there any if statement to compare the value? instead of where statement, can we use if after update the value become smaller than the value...

the ProdID has a value, the quantity has a fixed value, but how I can assign a variable value to POID?

Dear SS,

I have found the script of the table for insert

INSERT INTO [ProjectTesting].[dbo].[PurchaseOrder]

([POID]

...

Thanks really, SS, here is my schema of the purchaseOrder table

PurchaseOrder table

POrdID (PK)

ProdID (FK)

OrdQty

it is quite simple table.

SS, now, I have tried again, this time I get a red leggy under my column name 'inventoryQty', when my mouth over, I get this message,

Invalid column name...

SS I also have another concern, because the quantity still < 150, will this trigger keep insert?

sorry, end of 150 red leggy.

SS, I also get red leggie at the end os 150, maybe need to add something behind 150?