In this web design and programming video tutorial I will review a lot of what you have been taught previously. I’ll review many topics by showing you how to make drop down boxes that are populated from data stored in a database. If you don’t completely understand everything don’t worry about it. That’s why it is a review.
All of the code from the video follows the video. I included additional comments in the code that you can better understand what is going on. You also should print out the code and refer to it as you watch the video for better comprehension.
Here is a dump file for the database Database Dump File.
If you have any questions or comments leave them below, otherwise enjoy the video 🙂
Code From the Video
<?php
DEFINE (‘DBUSER’, ‘mysqladm’);
DEFINE (‘DBPW’, ‘Turtle2Dove’);
DEFINE (‘DBHOST’, ‘localhost’);
DEFINE (‘DBNAME’, ‘hamdb’);
if ($dbc = mysql_connect (DBHOST, DBUSER, DBPW)) {
if (!mysql_select_db (DBNAME)) { // If it can’t select the database.
// Handle the error.
trigger_error(“Could not select the database!<br />MySQL Error: ” . mysql_error());
exit();
} // End of mysql_select_db IF.
} else {
// Print a message to the user, and kill the script.
trigger_error(“Could not connect to MySQL!<br />MySQL Error: ” . mysql_error());
exit();
}
?>
<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN”
“http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd”>
<html xmlns=”http://www.w3.org/1999/xhtml” lang=”en” xml:lang=”en”>
<head>
<meta http-equiv=”Content-Type” content=”text/html; charset=ISO-8859-1″ />
<title>Products</title>
<script language=JavaScript>
// This function is called to reload the page and pass the values chosen by the user
function reload(form)
{
// Get the value of the dropdown named cat
var val=form.cat.options[form.cat.options.selectedIndex].value;
// Loads the new page with the stored variable values
self.location=’hamtest.php?cat=’ + val ;
}
function reload2(form)
{
var val=form.cat.options[form.cat.options.selectedIndex].value;
var val2=form.subcat.options[form.subcat.options.selectedIndex].value;
self.location=’hamtest.php?cat=’ + val + ‘&cat3=’ + val2 ;
}
</script>
</head>
<body>
<?php
// Getting the data from Mysql table for first list box
$quer1=mysql_query(“SELECT DISTINCT Prod_Type,PT_ID FROM Product_ID
WHERE PT_ID IN (0,1,2,3,4,7,8,14,15,16,31,32,33,34,35,36,37) order by PT_ID”);
// For second drop down list we will check if category is selected else we will display all the subcategory
$cat=@$_GET[‘cat’]; // This line is added to take care if your global variable is off
if(isset($cat) and strlen($cat) > 0){
$quer=mysql_query(“SELECT DISTINCT Manufacturer_ID.Manufacturer,Manufacturer_ID.Man_ID FROM Manufacturer_ID, Model_Numbers
where ((Manufacturer_ID.Man_ID = Model_Numbers.Man_ID) AND (Model_Numbers.PT_ID = $cat)) order by Manufacturer”);
}else{$quer=mysql_query(“SELECT DISTINCT Manufacturer,Man_ID FROM Manufacturer_ID order by Manufacturer”); }
// end of query for second subcategory drop down list box
// Â For Third drop down list we will check if sub category is selected else we will display all the subcategory3
$cat3=@$_GET[‘cat3’]; // This line is added to take care if your global variable is off
if(isset($cat3) and strlen($cat3) > 0){
$quer2=mysql_query(“SELECT DISTINCT Model_Num, Model_Num FROM Model_Numbers where ((Model_Numbers.Man_ID=$cat3) AND (Model_Numbers.PT_ID = $cat)) order by Model_Num”);
}else{$quer2=mysql_query(“SELECT DISTINCT Model_Num, Model_Num FROM Model_Numbers order by Model_Num”); }
// Â End of query for third subcategory drop down list box
echo “<form method=post name=f1 action=’confirm.php’>”;
// Â Starting of first drop downlist
echo “<select name=’cat’ Â onchange=\”reload(this.form)\”><option value=”>Select one</option>”;
while($results = mysql_fetch_array($quer1)) { Â // Fetch a row of data based on a query
if($results[‘PT_ID’]==@$cat){echo “<option selected value=’$results[PT_ID]’>$results[Prod_Type]</option>”.”<br />”;}
else{echo  “<option value=’$results[PT_ID]’>$results[Prod_Type]</option>”;}
}
echo “</select>”.”<br />”;
// Â Starting of second drop downlist
echo “<select name=’subcat’ Â onchange=\”reload2(this.form)\”><option value=”>Select one</option>”;
while($results2 = mysql_fetch_array($quer)) { // Fetch a row of data based on a query
if($results2[‘Man_ID’]==@$cat3){echo “<option selected value=’$results2[Man_ID]’>$results2[Manufacturer]</option>”.”<br />”;}
else{echo  “<option value=’$results2[Man_ID]’>$results2[Manufacturer]</option>”;}
}
echo “</select>”.”<br />”;
// Â This will end the second drop down list
echo “<select name=’subcat3′ ><option value=”>Select one</option>”;
while($results3 = mysql_fetch_array($quer2)) {
echo  “<option value=’$results3[Model_Num]’>$results3[Model_Num]</option>”;
}
echo “</select>”.”<br />”;
?>
<input type=submit name=Submit value=Submit>
</form>
</body>
</html>
