sql stored procedure, subtract or add to value

Question

0.00/5 (No votes)

See more:

Maybe i have a little brainfreeze on what to search for in google.

My question is defined like this:
I have table at sever. 2 columns: productNr,

curQuantity<br />

Troughout the day i have program which makes rapid changes to this table after user has decided to add or subtract to this amount.
Our current setup is like this.

SQL

Select-query to get curQuantity.
newQuantity = curQantity + (added or subtractet)
update-query to set newQantity.

I was thinking that this should be possible to do in one sql expression?
And therefor improve the efficiency of our program.

Posted 19-May-12 18:51pm

MrDeej

Updated 20-May-12 0:23am

Maciej Los

v2

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Accepted Answer · 2012-05-19T19:01:00

Solution 1

Yes:

SQL

DECLARE @OrigQuantity INT
SELECT TOP 1 @OrigQuantity = curQuantity FROM Products WHERE Id=3
UPDATE Products SET curQuantity = @OrigQuantity - 2 WHERE Id=3
SELECT @OrigQuantity

Posted 19-May-12 19:01pm

OriginalGriff

Comments

Maciej Los 20-May-12 6:24am

Good work, 5!