<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta http-equiv="X-UA-Compatible" content="ie=edge" />
<title>Document</title>
<script src="../public/jquery-3.3.1.min.js" type="text/javascript" charset="utf-8"></script>
</head>
<body>
<div id="sanji">
</div>
</body>
</html>
<script type="text/javascript">
$(document).ready(function(){
var str = "<select id=‘sheng‘></select><select id=‘shi‘></select><select id=‘qu‘></select>";
$("#sanji").html(str);
sheng();
shi();
qu();
$("#sheng").change(function(){//当元素的值发生改变时，会发生 change 事件。
shi();
qu();
})
$("#shi").change(function(){
qu();
})
})
function sheng(){
var pcode = "0";
var sheng_str = "";
$.ajax({
type:"post",
url:"chuli.php",
async:false,//是否异步
data:{
pcode:pcode
},
dataType:"json",
success:function(data){
for(var i=0;i<data.length;i++){
sheng_str +="<option value=‘"+data[i][0]+"‘>"+data[i][1]+"</option>";
}
$("#sheng").html(sheng_str);
}
});
}
function shi(){
var pcode = $("#sheng").val();
var shi_str = "";
$.ajax({
type:"post",
url:"chuli.php",
async:false,//是否异步
data:{
pcode:pcode
},
dataType:"json",
success:function(data){
for(var i=0;i<data.length;i++){
shi_str +="<option value=‘"+data[i][0]+"‘>"+data[i][1]+"</option>";
}
$("#shi").html(shi_str);
}
});
}
function qu(){
var pcode = $("#shi").val();
var qu_str = "";
$.ajax({
type:"post",
url:"chuli.php",
async:false,//是否异步
data:{
pcode:pcode
},
dataType:"json",
success:function(data){
for(var i=0;i<data.length;i++){
qu_str +="<option value=‘"+data[i][0]+"‘>"+data[i][1]+"</option>";
}
$("#qu").html(qu_str);
}
});
}
</script>
<?php $conn = new mysqli("localhost","root","","ceshi3"); $conn->connect_error?die():""; $pcode=$_POST[‘pcode‘]; $sql="select id,area_name from dt_area where area_parent_id = ‘{$pcode}‘"; $result= $conn->query($sql); $attr = $result->fetch_all(); echo json_encode($attr); ?>
原文：https://www.cnblogs.com/sunhao1987/p/9210531.html