update calcs

[Anon]

Would somebody please help me with this? I think the problem is in the expression (maybe some sort of quotation or bracketing) but I can't work out where.

$set = "SET qtos52 ='".(qtos52 - $orderqty[$count])."' ";

When used in the update, if qtos52 is 100 and $ordertqy is 1 I expect qtos52 to become 99.
Instead it comes out as -1

Any ideas?

Thanks

Chris

[tim_perdue]

$qtos52

You're missing the dollar sign

[Anon]

Are you sure I need it in this context? i.e. $set is used like so: $query = $update.$set.$where;

Also, qtos52 is a field from my database

I tried your suggestion as follows: -

$set = "SET qtos52 ='".($qtos52 - $orderqty[$count])."' ";

results in the same problem.

$set = "SET $qtos52 ='".($qtos52 - $orderqty[$count])."' ";

results in a syntax error.

Thanks

Chris

[smarlowe]

When in doubt, print it out!

print out your query before you execute it, then put in an exit statement after that. Cut and paste that statement into your interactive sql monitor for your dbms and see what error you get.

[stephanie]

did you try other synthax like :

<?

$set = "SET qtos52 = " . ($qtos52 - $orderqty[$count]);

?>

[Anon]

If it is a number field you shouldn't have single quotes around the value you are setting it to:
$set = "SET qtos52 ='".(qtos52 - $orderqty[$count])."' ";

should be

$set = "SET qtos52 =".(qtos52 - $orderqty[$count]);