question about delete statement

Hi,My question is :
CREATE TABLE t1
(c1 INTEGER,
c2 INTEGER,
c3 DECIMAL(15,0 ))
INSERT INTO t1 VALUES (1, 2, 3.0)
How can i define a SQL commend will cause C1 to be decremented each time a row is deleted from the T2 table?
Thanks !Can you give more details on what you are trying to do? I suspect that there are better ways to accomplish whatever you need to do.

To answer your question as it was posted, you could create a trigger on the T2 table that updated the T1 table appropriately. I'm a little vague on the implementation details because it seems that you are looking for more than a simple counter, and you haven't provided a lot of details on what you want to happen.

-PatP|||CREATE TRIGGER myTriggerForDelete
ON T2
AFTER DELETE
AS
UPDATE T1
SET C1=COALESCE((SELECT MIN(C1) FROM T1),0)-1|||It should be something like my previous post.

But as Pat said, I don't think this makes senses, maybe you should give us more explanations.

Hope it can helps you|||please go to books online and read the article on CREATE TRIGGER and pay special attention to the section on the inserted and deleted tables.|||Are you trying to prevent "holes" in a meaningless "key"|||Are you trying to prevent "holes" in a meaningless "key"

If it's the case you should read that:
http://guelphdad.wefixtech.co.uk/sqlhelp/gaps.shtml