来自MYSQL的php下拉菜单，如何返回其他列值？

I'm having a input form that asks for a location. The locations are stored in a mysql db and have an id (colomn: id and column: location).

I have a drop down menu that is generated from those records in the db:

    <select name="location">

    <?php                         
            $query="SELECT location FROM locations";
                $result=mysql_query($query) or die;

            while ($row=mysql_fetch_array($result)) {

            $location=$row['location'];

            echo "<option>$location</option>";
    ?>

    </select>

This all works. When the form is sumbitted, I obviously get a POST[location] for example "Belgium".

Let's say Belgium is the location in my db and has id 5, how can I return the ID as the POST variable from the dropdown box, instead of the location. Ofcourse I want the dropdown to show the locations, and not the ID's.

Thanks in advance!

Each option can take a value and show another string so use value="my_value" for each option inside the select tag

<select name="location">
    <?php                         
        $query="SELECT id, location FROM locations";
        $result=mysql_query($query);

        while ($row=mysql_fetch_array($result)) {
            echo "<option value=\"" . $row['id'] . "\">" . $row['location'] . "</option>";
        }
    ?>
</select>

now your POST['location'] will contain the db id for selected location

select ID from locations;

$ID=$row['ID'];

Replace ID by the ID-name of your column ofcourse.

If you say select * from locations you can do something like this:

$row['anyCOLUMNNAME']

You can choose any column you like and use that information from that particular row.

if you change the SQl query to include the ID of the location, you can assign that value to the dropdown selected value.

<select name="location">
<?php   
$query="SELECT id, location FROM locations";
$result=mysql_query($query) or die;
while ($row=mysql_fetch_array($result)) {

    $location=$row['location'];
    $id = $row['id'];
    echo "<option value='".$row['id']."'>".$location."</option>";
?>
</select>

<select name="location">
<?php                         
// select columns you need, separate by , (comma)
$query = "SELECT `column1`, `column2` FROM `locations`;";
$result = mysql_query($query) or die;
while ($row = mysql_fetch_array($result)) {
    // selected columns become accessible in $row array
    // value attribute needs to be escaped here
    echo '<option value="', htmlentities($row['column1']),'">',
        htmlentities($row['column2']), '</option>'; // escape label too
    // <option> does not accept HTML in label so it should be escaped
} // done!
?>
</select>

^ this (read comments for explanations)