<script language="javascript">
function college2major(collegeid)
{
var allcount=0;
majorarray=new array();
<?php
$sql="select * from major";
$result=mysql_query($sql);
$count=0;
while($myrow=mysql_fetch_array($result))
{
?>
majorarray[<?php =$count ?>]=new array(""<?php =$myrow['major_id']?>","<?php =$myrow['major_name'] ?>","<?php =$myrow['college_id'] ?>" );
<?php
$count++;
}
echo "allcount=$count";
?>
document.studentform.major.length=0;
document.studentform.major.options[document.studentform.major.length]=new option("选择专业","");
var collegeid=collegeid;
var i;
for(i=1;i<allcount;i++)
{
if(majorarray[i][2]==collegeid)
{
document.studentform.major.options[document.studentform.major.length]=new option(majorarray[i][1],majorarray[i][0]);
}
}
}function major2class(majorid)
{
var allcount=0;
classarray=new array();
<?php
$sql="select * from class";
$result=mysql_query($sql);
$count=0;
while($myrow=mysql_fetch_array($result))
{
?>
classarray[<?php =$count ?>]=new array(""<?php =$myrow['class_id']?>","<?php =$myrow['class_name'] ?>","<?php =$myrow['major_id'] ?>" );
<?php
$count++;
}
echo "allcount=$count";
?>
document.studentform.class.length=0;
document.studentform.class.options[document.studentform.class.length]=new option("选择班级","");
var majorid=majorid;
var i;
for(i=1;i<allcount;i++)
{
if(classarray[i][2]==majorid)
{
document.studentform.class.options[document.studentform.class.length]=new option(classarray[i][1],classarray[i][0]);
}
}
}
</script>
<select name="college" onchange="college2major(this.options[this.selectedIndex].value)">
<option selected value="">选择学院</option>
<?php
$sql="select * from college";
$result=mysql_query($sql);
while($myrow =mysql_fetch_array($result))
{
?>
<option value="<?php $myrow 1["college_id"];?>">
<?php echo $myrow ["college_name"];?>
</option>
<?php }?>
</select>
<select name="major" id="major" onchange="major2class(this.options[this.selectedIndex].value)">
<option selected value="">选择专业</option>
</select><select name="class"id="class" >
<option selected value="">选择班级</option>
</select>数据库中的college里college_id是主键；major里major_id是主键，college_id是college里的外键；class里的class_id是主键，major_id是major里的外键我咋不能实现关联，哪错了？？求解
function college2major(collegeid)
{
var allcount=0;
majorarray=new array();
<?php
$sql="select * from major";
$result=mysql_query($sql);
$count=0;
while($myrow=mysql_fetch_array($result))
{
?>
majorarray[<?php =$count ?>]=new array(""<?php =$myrow['major_id']?>","<?php =$myrow['major_name'] ?>","<?php =$myrow['college_id'] ?>" );
<?php
$count++;
}
echo "allcount=$count";
?>
document.studentform.major.length=0;
document.studentform.major.options[document.studentform.major.length]=new option("选择专业","");
var collegeid=collegeid;
var i;
for(i=1;i<allcount;i++)
{
if(majorarray[i][2]==collegeid)
{
document.studentform.major.options[document.studentform.major.length]=new option(majorarray[i][1],majorarray[i][0]);
}
}
}function major2class(majorid)
{
var allcount=0;
classarray=new array();
<?php
$sql="select * from class";
$result=mysql_query($sql);
$count=0;
while($myrow=mysql_fetch_array($result))
{
?>
classarray[<?php =$count ?>]=new array(""<?php =$myrow['class_id']?>","<?php =$myrow['class_name'] ?>","<?php =$myrow['major_id'] ?>" );
<?php
$count++;
}
echo "allcount=$count";
?>
document.studentform.class.length=0;
document.studentform.class.options[document.studentform.class.length]=new option("选择班级","");
var majorid=majorid;
var i;
for(i=1;i<allcount;i++)
{
if(classarray[i][2]==majorid)
{
document.studentform.class.options[document.studentform.class.length]=new option(classarray[i][1],classarray[i][0]);
}
}
}
</script>
<select name="college" onchange="college2major(this.options[this.selectedIndex].value)">
<option selected value="">选择学院</option>
<?php
$sql="select * from college";
$result=mysql_query($sql);
while($myrow =mysql_fetch_array($result))
{
?>
<option value="<?php $myrow 1["college_id"];?>">
<?php echo $myrow ["college_name"];?>
</option>
<?php }?>
</select>
<select name="major" id="major" onchange="major2class(this.options[this.selectedIndex].value)">
<option selected value="">选择专业</option>
</select><select name="class"id="class" >
<option selected value="">选择班级</option>
</select>数据库中的college里college_id是主键；major里major_id是主键，college_id是college里的外键；class里的class_id是主键，major_id是major里的外键我咋不能实现关联，哪错了？？求解
数据表说明：三个字段id、name、parent_id
可以不连后台，拿测试数据试一下
后台部分：<?php
/*
*说明：联动菜单
*/
require(xxx);
$add_result = mysql_query("select * from xxx");
$add_result_num = mysql_num_rows($add_result);
echo '<script type="text/javascript">var name_array,parent_array,id_array;name_array=new Array();parent_array=new Array();id_array=new Array();';
for($i = 0; $i < $add_result_num; $i++){
mysql_data_seek($add_result,$i);
$add_result_information = mysql_fetch_array($add_result);
echo 'id_array['.$i.']='.$add_result_information['xxx'].';';
echo 'name_array['.$i.']='.$add_result_information['xxx'].';';
echo 'parent_array['.$i.']='.$add_result_information['xxx'].';';
}
echo '</script>';
?>前台部分：<html>
<head>
<title>测试</title>
<script type="text/javascript">
//*测试数据
var id_array,name_array,parent_array;
id_array = new Array(1,2,3,4,5,6,7,8,9,10,11,12,13,14);
name_array = new Array("湖北","广东","黄冈","武汉","东莞","虎门","浠水","蕲春","武昌","汉阳","东一","东二","虎一","虎二");
parent_array = new Array(0,0,1,1,2,2,3,3,4,4,5,5,6,6);/****三级版****/
function create_select(parent_id,sel_id,what_sel){
var new_option;
if(parent_id === ""){
return;
}
if(what_sel == 1){
document.getElementById("mid_sel").options.length = 0;
document.getElementById("bot_sel").options.length = 0;
new_option = new Option("请选择地区","");
document.getElementById("mid_sel").options.add(new_option);
new_option = new Option("请选择县市","");
document.getElementById("bot_sel").options.add(new_option);
}
if(what_sel == 2){
document.getElementById("bot_sel").options.length = 0;
new_option = new Option("请选择县市","");
document.getElementById("bot_sel").options.add(new_option);
}
for(var j = 0; j < id_array.length; j++){
if(parent_array[j] == parent_id){
new_option = new Option(name_array[j],id_array[j]);
document.getElementById(sel_id).options.add(new_option);
}
}
}
/****无限级版****/
//获取上一级id
function get_top_id(the_id){
for(var i = 0; i < id_array.length; i++){
if(the_id == id_array[i]){
return parent_array[i];
break;
}
}
}
//获取下一级id
function get_bottom_id(the_id){
var c_array = new Array();
var n = 0;
for(var i = 0; i < parent_array.length; i++){
if(the_id == parent_array[i]){
c_array[n] = id_array[i];
n++;
}
}
if(n > 0){
return c_array;
}else{
return false;
}
}
//生成下拉菜单代码
function create_sel(the_id){
the_id = Number(the_id);
var node_array,option_array,sel_name,head_code,last_code,sel_code;
document.getElementById("set_sel").innerHTML = '';
var node_array = new Array();
var n = 0,loop_go_on = the_id;
while(loop_go_on != 0){
node_array[n] = get_top_id(loop_go_on);
loop_go_on = node_array[n];
n++;
}
node_array.unshift(the_id);
head_code = '<form method="post" action="">';
last_code = '</form>';
sel_code = '';
for(var k = node_array.length - 1; k >= 0; k--){
option_array = get_bottom_id(node_array[k]);
if(option_array !== false){
sel_name = 'select' + node_array[k];
sel_code += '<select name="' + sel_name + '" onchange="create_sel(this.value)">';
for(var l = 0; l < option_array.length; l++){
for(var m = 0; m < id_array.length; m++){
if(option_array[l] == id_array[m]){
if(id_array[m] == node_array[k - 1]){
sel_code += '<option value=' + id_array[m] + ' selected>' + name_array[m] + '</option>';
}else{
sel_code += '<option value=' + id_array[m] + '>' + name_array[m] + '</option>';
}
break;
}
}
}
sel_code += '</select>';
}
}
document.getElementById("set_sel").innerHTML = head_code + sel_code + last_code;
}
</script>
</head><body onLoad="create_sel(5)">
<form name="create_sel" method="post" action="create_sel.php">
<select id="top_sel" name="top_sel" onChange="create_select(this.value,'mid_sel',1)">
<option value="">请选择省份</option>
</select>
<select id="mid_sel" name="mid_sel" onChange="create_select(this.value,'bot_sel',2)">
<option value="">请选择地区</option>
</select>
<select id="bot_sel" name="bot_sel">
<option value="">请选择县市</option>
</select>
</form>
<div id="set_sel"></div>
</body>
</html>
<form name="my_form" method="post" action="create_sel.php">