trouble updating WHERE 2 columns must have a certain value

[boo_lolly]

i'm trying to update my table, but the coordinates must fall under TWO specifications. not just one. i'm having trouble figuring out how to do this. my code:
[code]
<?php
        if(isset($_POST['selected_value'])){
                $sql = "UPDATE item_options_linked
                        SET selected_value_id = ". $_POST['selected_value'] ."
                        WHERE (item_id = ". $_GET['itemID'] ." &&
                              option_id = ". $_POST['option_id'] .")";

                mysql_query($sql) OR die(mysql_error());
        }
?>
[/code]

my table:
[code]
mysql> SELECT * FROM item_options_linked;
+-----+---------+-----------+-------------------+
| id  | item_id | option_id | selected_value_id |
+-----+---------+-----------+-------------------+
|  13 |      6 |        6 |              NULL |
|  14 |      0 |        5 |              NULL |
|  9 |      4 |        5 |              NULL |
|  11 |      6 |        5 |              NULL |
|  10 |      4 |        6 |              NULL |
|  15 |      0 |        6 |              NULL |
|  17 |      7 |        5 |              NULL |
|  18 |      7 |        6 |              NULL |
|  19 |      4 |        8 |              NULL |
|  20 |      6 |        8 |              NULL |
|  21 |      7 |        8 |              NULL |
+-----+---------+-----------+-------------------+
[/code]
where are my mistake(s)?

[hvle]

if all columns in your item_options_linked user integer, then your query has no error.

I would echo the query to make sure it got the $_GET and $_POST right.

[boo_lolly]

[quote author=hvle link=topic=123572.msg510987#msg510987 date=1169509988]
if all columns in your item_options_linked user integer, then your query has no error.

I would echo the query to make sure it got the $_GET and $_POST right.
[/quote]
i figured it out:
[code]
<?php
        if(isset($_POST['selected_value'])){
                $sql = "UPDATE item_options_linked
                        SET selected_value_id = ". $_POST['selected_value'] ."
                        WHERE (item_id = '". $_GET['itemID'] ."' AND
                              option_id = '". $_POST['option_id'] ."')";

                mysql_query($sql) OR die(mysql_error());
        }
?>
[/code]

[hvle]

actually, if the fields type is number, integer, you do not need to wrap it single quote.

[boo_lolly]

[quote author=hvle link=topic=123572.msg510990#msg510990 date=1169510569]
actually, if the fields type is number, integer, you do not need to wrap it single quote.
[/quote]
true, but item_id and option_id, i believe are VARCHAR, it doesn't hurt. the single quotes and the && -> AND was the source of the problem.

[hvle]

umm... && is not a problem.

It's definitely the varchar type in item_id and option_id.

[fenway]

That shouldn't matter... it does silent type conversion anyway.

[hvle]

you're right again,
and now, I failed to see any error on the original query.

[fenway]

Switch it to a SELECT, make sure that you get some matching rows...