[SOLVED] how to subtract a field from a number

[berry05]

say my field is 100 and i subtract 50 from it..how would i do that?

i have this code but i know its not right

 

$increment = "UPDATE users SET gold = gold - "50"";
mysql_query($increment,$connect);

[DarkWater]

UPDATE users SET gold = gold - 50;

 

That will lower EVERYONE'S gold by 50, so you probably want a WHERE clause.

[berry05]

i tried something like this..

	  UPDATE users WHERE username ='$Username' AND  SET gold = gold - 50;

 

and i get error..

Parse error: syntax error, unexpected T_STRING in C:\wamp\www\test\login\hoe.php on line 47

[premiso]

$increment = "UPDATE users SET gold = (gold - 50) WHERE username = '" . $username . "'";
mysql_query($increment,$connect);

 

Make sure $username is either $Username or $username, be consistent through out the code.

[berry05]

thxs!

[twm]

in my view it is better to use id numbers not usernames. If you set up your id field as the primary and increment, it should not have duplicates no matter what.