multiple select drop down with mysql & php

[nagasea]

<select name="selectName" size="4" multiple>
<option value="first">first</option>
<option value="second">second</option>
<option value="third">third</option>
</select>

With database like this :
ID POSITION
1 first
2 first
3 second
4 first
5 second
6 third

ok , here's the question.
I want to use multiple select (using ctrl to hold the option value first and third)
then, query it to database and display only position first and third.

Anybody can show me how to do this task ?
thanks

[Weedpacket]

First of all, rename your select field to end with []; then $_POST['selectName'] will be an array of the selected values.

Now, since that is coming from the outside world, we need to check its validity.

$selectName = array();
foreach($_POST['selectName'] as $selected)
 if(is_int($selected) $selectName[]=$selected;

And if count($selectName)>0, stick it into the MySQL query

"...WHERE thefield IN (".join(',',$selectName).")"

[nagasea]

mm.. im not following..
can you guide me more on your method please

[nagasea]

Hi weed/anyone else.
Still can't figure out how to make it works
here's the code :

<?
$GIVETOWHO = "SELECT DISTINCT(cat4) FROM `book`";
$TOWHO = mysql_query($GIVETOWHO);
echo "<select name=cat4_drop size=6 multiple>";
while ($XX = mysql_fetch_array($TOWHO))
{ echo "  <option value=\"$XX[cat4]\">$XX[cat4]</option>"; }
echo "<option value=\"\">------------------------------</option> </select> ";
?>

and then on the next page (form action)

$cat1_drop = array();
foreach($_POST['cat1_drop'] as $selected;)

if(is_int($selected)) $cat1_drop[]=$selected;

if (count($cat1_drop)>0)

echo "$cat1_drop";

it;s still not working, can someone help me.

[Weedpacket]

echo '<select name="cat4_drop[]" size="6" multiple>';

Thought I mentioned that.