Раскрывающийся список (заполненный данными MySQL) и данные второго раскрывающегося списка (заполненные данными MySQL) будут основаны на первом раскрывающемся списке, а данные третьего раскрывающегося списка (заполненные данными MySQL) будут основываться на 2-й выпадающий список ..
Я создал 2 раскрывающихся списка, но когда я попробовал третий раскрывающийся список, я не могу заставить его работать. Вот мой полный исходный код
Пример этого вы можете найти здесь: http://www.plus2net.com/php_tutorial/dd3.php
<?php
require "config.php"; // Your Database details
?>
<!doctype html public "-//w3c//dtd html 3.2//en">
<html>
<head>
<SCRIPT language=JavaScript>
function reload(form)
{
var val=form.cat.options[form.cat.options.selectedIndex].value;
self.location='aw.php?cat=' + val ;
}
function reload3(form)
{
var val=form.cat.options[form.cat.options.selectedIndex].value;
var val2=form.subcat.options[form.subcat.options.selectedIndex].value;
self.location='aw.php?cat=' + val + '&cat3=' + val2 ;
}
</script>
</head>
<body>
<?
///////// Getting the data from Mysql table for first list box//////////
$quer2=mysql_query("SELECT DISTINCT StudNo,LName,FName,MName,Course FROM students");
///////////// End of query for first list box////////////
/////// 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){
$quer=mysql_query("SELECT DISTINCT GSCode,GStudNo,GSem,GYear,Grade FROM grade WHERE GStudNo='$cat' order by GSCode");
}else{$quer=mysql_query("SELECT DISTINCT GSCode,GStudNo,GSem,GYear,Grade FROM grade order by GSCode"); }
////////// end of query for second subcategory drop down list box ///////////////////////////
$quer2=mysql_query("SELECT DISTINCT GSCode,GStudNo,GSem,GYear,Grade FROM grade");
/////// for Third drop down list we will check if sub category is selected else we will display all the subcategory3/////
$cat3=$_GET['subcat']; // This line is added to take care if your global variable is off
if(isset($cat3) and strlen($cat3) > 0){
$quer3=mysql_query("SELECT DISTINCT GSem,GYear,Grade FROM grade where GSCode='$cat3'");
}else{$quer3=mysql_query("SELECT DISTINCT GSem,GYear,Grade FROM grade"); }
////////// end of query for third subcategory drop down list box ///////////////////////////
echo "<form method=post name=f1 action='dd3ck.php'>";
////////// Starting of first drop downlist /////////
echo "<select name='cat' onchange=\"reload(this.form)\"><option value=''>Select one</option>";
while($noticia2 = mysql_fetch_array($quer2)) {
if($noticia2['StudNo']==@$cat){echo "<option selected value='$noticia2[StudNo]'>$noticia2[StudNo]</option>"."<BR>";}
else{echo "<option value='$noticia2[StudNo]'>$noticia2[StudNo]</option>";}
}
echo "</select>";
////////////////// This will end the first drop down list ///////////
////////// Starting of second drop downlist /////////
echo "<select name='subcat' onchange=\"reload3(this.form)\"><option value=''>Select one</option>";
while($noticia = mysql_fetch_array($quer)) {
if(empty($noticia['Grade']) AND $noticia['GSCode']==@$cat3){echo "<option selected value='$noticia[GSCode]'>$noticia[GSCode]</option>"."<BR>";}
else{echo "<option value='$noticia[GSCode]'>$noticia[GSCode]</option>";}
}
echo "</select>";
////////////////// This will end the second drop down list ///////////
////////// Starting of third drop downlist /////////
echo "<select name='subcat3' ><option value=''>Select one</option>";
while($noticia = mysql_fetch_array($quer3)) {
echo "<option value='$noticia[GSem]'>$noticia[GSem]</option>";
}
echo "</select>";
////////////////// This will end the third drop down list ///////////
echo "<input type=submit value='Submit the form data'></form>";
?>
</body>
</html
>