PHP Syntax

[mysql_query]

I have a MySQL database with a value in a certain row and a certain column. I use the 'update' query to update it (obviously). Now, how would I do this: I have a numerical a value in a column, and I want to add to that number a number from a form. I know in C, this is done like this:

current=current+variable;

The two "currents" are the same (they are in my db), and the variable comes from the form. Right now, I have this:

$query = "UPDATE roster SET hours = '$hours' WHERE callsign='$callsign'"; 
$resultat = mysql_db_query($db, $query, $connection) or 
die("Error in query." .mysql_error()); 
} 

I want this: (notice hours)

$query = "UPDATE roster SET hours = hours+'$hours' WHERE callsign='$callsign'"; 
$resultat = mysql_db_query($db, $query, $connection) or 
die("Error in query." .mysql_error()); 
} 

This syntax does not work. Can anyone tell me how to do this properly?

[bastien]

update the sucker....

select the item from the DB

add the items together

update the row

[mysql_query]

Hi.

Can you give some snippet of a code?

Thanks.

[sarahk]

$query = "UPDATE roster SET hours = hours+$hours WHERE callsign='$callsign'"; 

When in doubt, echo it out.

You were trying to pass $hours as a string and therefore add a number and a string.

Had you echo'd it out I'm sure you would have seen it, or you could have copied it into your database gui (phpMyAdmin) and it would have told you what the problem was and you could then have updated your code.

[mysql_query]

Yep, that works. Thank you very much.