jQuery+PHP+MySQL实现无限级联下拉框效果

本文简单实现jQuery无限级联效果，分享给大家供大家参考，具体内容如下
 效果图：

　图1 仅下拉框

　 图2 层级提示+下拉框

图3 存储数据点击响应

主要包含3个文件：index.html（主页），wuxianjilian.php（数据处理），wuxianjilian.sql（MySQL数据文件）
1. index.html

<html>
<head>
 <title>无限级联</title>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <meta http-equiv="Content-Language" content="zh-CN" />
 <script type="text/javascript" src="http://files.cnblogs.com/Zjmainstay/jquery-1.6.2.min.js"></script>
</head>
<body>
<div id="jilianContainer"></div>
<script type="text/javascript">
$(document).ready(function(){
 var getData = function(obj){
  $.ajax({
   url:'wuxianjilian.php',
   type:'POST',
   data:{"pid":obj.val()},
   dataType:'json',
   async:false,
   success:function(data){
    if($(".selection").length){
     $(".selection:gt("+$(obj).index()+")").remove(); //移除后面所有子级下拉菜单
     $(".selection:last").after(data);     //添加子级下拉菜单
    }else {
     $("#jilianContainer").append(data);     //初始加载情况
    }
    //所有下拉响应
    $(".selection").unbind().change(function(){
     getData($(this));
    });
   },
   error:function(msg){
    alert('error');
   }
  });
 }

 //Init
 getData($(this));

});
</script>

<!-- 数据存储示例，仅提取数据，不做操作 -->

<div style="height:100px;display:block;"></div>
<input type="button" value="存储数据" id="save"></input>
<script type="text/javascript">
$(document).ready(function(){
 $("#save").click(function(){
  var data = [];
  $(".selection").each(function(){
   data.push($.trim($(this).val()));
  })

  alert(data.join(','));
 });
});
</script>

</body>
</html>

2. wuxianjilian.php

<?php
 header("Content-type: text/html; charset=utf-8"); 

 //数据库连接操作
 $conn = mysql_connect("localhost","Zjmainstay","") or die("Can not connect to database.Fatal error handle by ". __FILE__);
 mysql_select_db("test",$conn);   //数据库名为 test
 mysql_query("SET NAMES utf8",$conn);

 //获取父级id
 $pid = (int)$_POST['pid'];

 //查询子级
 $sql = "SELECT id,text FROM `wuxianjilian` WHERE pid={$pid}";
 $result = mysql_query($sql,$conn);

 //组装子级下拉菜单
 $html = '';
 while($row = mysql_fetch_assoc($result)){
  $html .= '<option value="'.$row['id'].'">'.$row['text'].'</option>';
 }

 if(!empty($html)) $html = '<select class="selection"><option value="">请选择</option>' . $html . '</select>';

 //输出下拉菜单
 echo json_encode($html);
//End_php

3. wuxianjilian.sql

wuxianjilian.sql
/*
Navicat MySQL Data Transfer

Source Server   : localhost
Source Server Version : 50516
Source Host   : localhost:3306
Source Database  : test

Target Server Type : MYSQL
Target Server Version : 50516
File Encoding   : 65001

Date: 2012-10-24 20:59:09
*/

SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for `wuxianjilian`
-- ----------------------------
DROP TABLE IF EXISTS `wuxianjilian`;
CREATE TABLE `wuxianjilian` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `pid` int(11) DEFAULT NULL,
 `text` varchar(32) DEFAULT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=22 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of wuxianjilian
-- ----------------------------
INSERT INTO `wuxianjilian` VALUES ('1', '0', 'A0');
INSERT INTO `wuxianjilian` VALUES ('2', '0', 'B0');
INSERT INTO `wuxianjilian` VALUES ('3', '1', 'C1');
INSERT INTO `wuxianjilian` VALUES ('4', '1', 'D1');
INSERT INTO `wuxianjilian` VALUES ('5', '1', 'E1');
INSERT INTO `wuxianjilian` VALUES ('6', '2', 'F2');
INSERT INTO `wuxianjilian` VALUES ('7', '2', 'G2');
INSERT INTO `wuxianjilian` VALUES ('8', '3', 'H3');
INSERT INTO `wuxianjilian` VALUES ('9', '3', 'I3');
INSERT INTO `wuxianjilian` VALUES ('10', '3', 'J3');
INSERT INTO `wuxianjilian` VALUES ('11', '3', 'K3');
INSERT INTO `wuxianjilian` VALUES ('12', '4', 'L4');
INSERT INTO `wuxianjilian` VALUES ('13', '4', 'M4');
INSERT INTO `wuxianjilian` VALUES ('14', '8', 'N8');
INSERT INTO `wuxianjilian` VALUES ('15', '9', 'N9');
INSERT INTO `wuxianjilian` VALUES ('16', '14', 'O14');
INSERT INTO `wuxianjilian` VALUES ('17', '14', 'P14');
INSERT INTO `wuxianjilian` VALUES ('18', '14', 'Q14');
INSERT INTO `wuxianjilian` VALUES ('19', '17', 'R17');
INSERT INTO `wuxianjilian` VALUES ('20', '17', 'S18');
INSERT INTO `wuxianjilian` VALUES ('21', '20', 'T20');

如果大家还想深入学习，可以点击jquery下拉框效果汇总、JavaScript下拉框效果汇总进行学习。

希望本文所述对大家学习jquery程序设计有所帮助。