php dynamic select drop down menu

randombar

Hi Lads,

I've found a few of these online I guess I'm just wondering where I could find the most straightforward?

I will basically have a parent select drop down menu, then a child select drop down menu and another below that?

I would prefer to query the database after the selection has been made.

Thanks
Gary

seamus

Javascript is really the man for this.

You have two options -
One is to load in all of the possible child options to javascript, grouped into arrays. Create an onChange() handler for the parent drop-down, which updates the contents of the child drop-down when the parent one changes.

A neater (and cooler) way to do it is to use AJAX. When the parent drop-down changes, javascript goes back to the server and retrieves a list of child elements. You then load these into the child drop-down.

There's a good AJAX primer on www.w3schools.com that should get you started quickly.

randombar

Thanks for introduction me to Ajax, a new language for me to explore, it seems class! Anyways I better now start my Ajax quesitons:

How do I get the result of my database query to spit into the select options? I guess I wouldnt be 100% at divs

<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
etc
etc

Also how do I spit the results of my mysql query into a slectable drop down list like google suggestions?

Any help will be appreciated.

Gary

philologos

you could do it using a while loop.
[PHP]
$query = "select * from whatever";
$result = mysql_query($query);
$numrows = mysql_num_rows($result);
$i = 0;
while ($i < $numrows) {
$field = mysql_result($result, $i, "field");
echo "<option value='$i'>$field</option>";
$i++;
}
?>[/php]