PHP Populate dropdown menu values from database - php

Question

I am a beginner trying to ouptut the values of dropdown menu from a database. I already automatically generate the values from database but the problem i am having is I want the the value that is being selected to be displayed.
Ideally im trying to update a Subject which I want to data to be displayed in an HTML page where each item could be updated. What i need is to be able to select the 'position' of the subject that is beeing selected.
Here is my code:
<p>Position:
<select name="position">
<?php
$sel_subject = get_all_subjects();
$subject_count = mysql_num_rows($sel_subject);
//$subject_count+1 because we are adding a subject
for($count=1; $count <= $subject_count+1; $count++) {
echo "<option value=\"{$count}\"";
if($sel_subject['position'] == $count) {
echo " selected='selected'";
}
echo ">{$count}</option>";
}
?>
</select>

Answer 1

You seem to be relying on $count to be some internal ID that remains static; given that it's just a monotonically advancing integer, this seems like a risky proposition. However, if you're comfortable with that, all you need to do is change the value in the last echo statement to be the subject name instead of $count. I would instead encourage you to use something meaningful to the database - for example, some people create an auto_increment field called subject_id and key off of that; others like to use UUIDs.
I would also generally suggest using a foreach loop instead of a for loop, as it tends to simplify the code (you don't have to worry about maintaining the counter, or creating fence post errors, etc.) Here's a brief example - I'm guessing a bit at what the actual data is that is available to you, hopefully you can extrapolate it to what you actually have.
<p>Position:
<select name="position">
<?php
$sel_subject = get_all_subjects();
foreach($sel_subject as $subject_num => $subject) {
echo '<option value="', $subject_num, '"';
if ($subject['selected']) {
echo 'selected="selected"';
}
echo '>', $subject['subject_name'], '</option>';
}