add 30 days before trigger date programatically?

this is my query
SELECT ID, Contractname, triggerdate, Amount, ClientID FROM legalcontract
triggerdate is the date where we need to follow up to client for possible renewal.   i want to add to my query a field called 30days  which is 30 days before the triggerdate.  

how can u add that programmaticaly in tsql?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

You can pass a negative to the DATEADD function to perform a date subtraction:

SELECT DATEADD(day, -30, triggerdate) AS 30days
FROM legalcontract

gianitooAuthor Commented:
can my query look like this  
SELECT ID, DATEADD(day, -30, triggerdate) AS 30days, triggerdate,Contractname, startdate, enddate, Amount, ClientID FROM legalcontract
Yes, you can add that as a column anywhere in your SQL


Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Scott PletcherSenior DBACommented:
I know the answer has already been accepted but you want still want to consider this approach :-) ...

I suggest using a computed, or virtual, column.  This will keep the column definition in the table itself and not in any particular SELECT.  First, you add the column definition once to the table:

ALTER TABLE legalcontract
ADD notifydate AS DATEADD(DAY, -30, triggerdate)

Then you can SELECT it just like any other column.  For example:

SELECT ID, Contractname, notifydate, Amount, ...
FROM legalcontract
WHERE notifydate ...
ORDER BY notifydate
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft SQL Server 2005

From novice to tech pro — start learning today.