How to create select option from database? - php

Question

I'm working on a form that has 4 different select elements from 2 tables of a database. I haven't done anything like this and I don't really know how to do it.
I have a table called "students" from I need "name" and "class" and a table called "books" from I need "writer" "title" ... all is one select element and all has more than 2 option values.
I've tried with only one sql query and one select but it shows only one option on the site, wether it has about 6 values in the database.
My code:
$sql = "SELECT class
FROM students";
$result = mysql_query($sql);
while ($row = mysql_fetch_assoc($result)) {
$select_class = "<option value={$row['class']}>{$row['class']}</option>";
}
<select id="class" name="class">
<?php print $select_class; ?>
</select>
How would it be correct?

Answer 1

try this
$sql = "SELECT class FROM students";
$result = mysql_query($sql);
echo '<select id="class" name="class">';
while ($row = mysql_fetch_assoc($result)) {
echo "<option value={$row['class']}>{$row['class']}</option>";
}
echo '</select>';

Answer 2

You are overwriting $select_class on each while() loop. You need to concatenate $select_class . Change to $select_class .=
$select_class = "";
while ($row = mysql_fetch_assoc($result)) {
$select_class .= "<option value={$row['class']}>{$row['class']}</option>";
}

Answer 3

Changing this:
$select_class = "<option value={$row['class']}>{$row['class']}</option>";
to this:
$select_class .= "<option value={$row['class']}>{$row['class']}</option>";
might solve your problem.
Right now you are constantly resetting the value of $select_class, instead of adding to it. The .= assignment should help you get around this.
As always, be sure to up-vote any StackOverflow answers you find useful.

Answer 4

Try this
<?php
$dbhandle = mysql_connect($hostname, $username, $password) or die("can't connect");
$table = "students";
$sql = "SELECT * FROM students";
$result = mysql_query($sql, $dbhandle);
mysql_data_seek($result, 0);
?>
<form>
<select class="dropdown" name="dropdown">
<?php
if(mysql_num_rows($result) > 0){
while($row = mysql_fetch_array($result)) {
echo '<option value="' . $row['class'] . '">' . $row['class'] . '</option>';
}
}
?>
</select>
</form>