Updating a Particular Row

[Warptweet]

Is it possible for me to increase the number value in a column of a particular row in my mysql database by a specific value?

 

mysql_query("UPDATE users SET userspace += '50'
WHERE username = 'username'");

 

Is that possible? To simply increase like that?

If not, how can I?

[trq]

mysql_query("UPDATE users SET userspace = userspace+50 WHERE username = 'username'");