[RESOLVED] MySQL addition and subtraction

KingSky

I'm trying to create a code that decreases or increases the value of a "money" field for a specific row in a database, but I can't quite crack the syntax :o.

As with most things I attempt it's probably the simplest thing you could imagine yet it escapes me, and I realise this is probably the most noobish question one could possibly ask, so thank you for reading, let alone posting. 🙂

laserlight

What did you try?

KingSky

Errm, well just plus and minus actually :o

laserlight

As in, what exactly did you try?

KingSky

Erm,

mysql_query("UPDATE users SET money-'50000' WHERE userid='$id'") or die(mysql_error());

benracer

Try this...

UPDATE `users` SET `money`='money'-50000

KingSky

benracer wrote:
Try this...
UPDATE `users` SET `money`='money'-50000

This didn't work, the "money" value remained as it was before. Thank you though 🙂

benracer

Do it with php,

use a select statement first then update in a loop, you could use a percentage to increase the value...

$query = "UPDATE items SET price=price * 0.8"; // removes 20%
$query1 = "UPDATE items SET price=round(price,2)"; // rounds the price to currency type

KingSky

benracer wrote:
Do it with php,

use a select statement first then update in a loop, you could use a percentage to increase the value...
$query = "UPDATE items SET price=price * 0.8"; // removes 20%
$query1 = "UPDATE items SET price=round(price,2)"; // rounds the price to currency type

That changed nothing either 🙂

benracer

you did change the column names?

KingSky

Yes.