Using a Combobox as part of a query

[Loque]

Hi all,

I am a bit of a novice to php, but I've ended up building a database to report answers to a quiz that I have built. The problem is that I need to be able to select which person took which quiz, and then to be able to display their results.

The only real way I have thought of doing this is to use a dropdown box to select which people took the quiz, then run it through a query to output the results.

In essence I need a dropdown box that's connected to my database, and then I need to be able to store the result as a variable so that I can call on it in the query. How would I do this?

I have looked around Google and come up with a way of populating the combobox from my server, my code is:

<?php

// connect to the db server
$link = mysql_connect('localhost', 'root', 'root');
if (!$link) {
 die('Could not connect to database server. Died with this error: ' . mysql_error());
} else {
 echo('Successfully connected to the database.<br />');
}

// select the db
mysql_select_db('cp2db');


// drop down box info
$sql="SELECT id, tblLastName, FROM tblCore"; 
$result=mysql_query($sql); 

$options=""; 

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

 $id=$row["id"]; 
 $lastname=$row["tblLastName"]; 

 $options.="<OPTION VALUE=\"$id\">".$lastname; 
} 
?> 
Helloworld!

<SELECT NAME=thing> 
<OPTION VALUE=0>Choose 
<?=$options?> 
</SELECT> 

Unfortunately I have not be able to get this to work, can anybody point out the errors and possibly elaborate on how I could get the variable out?

Thanks for your help.

[rocknbil]

Welcome aboard Loque, "as is" I think all you need is

<?php echo $options; ?>

Short tags are deprecated.

A slightly improved version, though,

<?php 
// May not need it here, but becomes handy and good habit. 
// If there is a selected item, set a variable for it. 
$selected = isset($_POST['id'] and is_numeric($_POST['id']) and ($_POST['id'] > 0))?$_POST['id']:null; 
$options=null; // To squelch concatenation errors, = "" is fine too 
// drop down box info 
$sql="SELECT id, tblLastName, FROM tblCore"; 
$result=mysql_query($sql) or die("Could not query database for select list"); 
while ($row=mysql_fetch_array($result)) { 
 $id=$row["id"]; 
 $lastname=$row["tblLastName"]; 
 $options.="<option value=\"$id\""; 
 // HTML 4/5, ' selected="selected" ' for XHTML 
 if ($id==$selected) { $options .= ' selected'; } 
 $options .= ">$lastname</option>\n"; 
} 
if ($options) { 
 echo "<p>Helloworld!</p> 
 <p>label for=\"thing\">Thing:</label> <select name=\"thing\" id=\"thing\"> 
 <option value=\"0\">Choose</option> 
 $options 
 </select> </p> 
 "; 
} 
else { echo "<p>No options to show.</p>"; } 

Notes:
- As mentioned, shorttags are deprecated, use <?php
- Scalar $variables will interpolate in double quotes, save debugging time by removing concatenations where you don't need them.
- Output validation is important, always quote attributes (value=\"0\") and note the usage of label
- Error trapping is your friend, note the if/else