Jump to content

Archived

This topic is now archived and is closed to further replies.

OriginalSunny

reducing the count for an item in a column

Recommended Posts

Hi,
I am trying to reduce a number in my column by 1. I need to do this as on my php script when someone buys a product the amount should reduce by 1. I have tried the following:

update [i]tablename[/i] set amount = 'amount' - 1 where ID = '005';

update [i]tablename[/i] set amount = 'amount - 1' where ID = '005';

The first statement doesnt changes the amount to -1. The second statement sets the amount to 0. What statement should i be using in mysql?? as i then need to use the statement in my php page.

Share this post


Link to post
Share on other sites
Using single quotes (') makes MySQL think it's a string. Just treat it like a column name both times.

[code]update tablename set amount = amount - 1 where ID = '005';[/code]

Share this post


Link to post
Share on other sites

×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.