ajax php实现三级联动的方法
发布时间：2020-08-19 09:34:43
来源：亿速云
阅读：106
作者：小新
小编给大家分享一下ajax php实现三级联动的方法，希望大家阅读完这篇文章后大所收获，下面让我们一起去探讨吧！ajax php实现三级联动的方法：首先创建一个test数据库并创建三张表；然后初始化所有的省份；接着把当前的省份id通过ajax发出请求传递到服务端的程序中；最后查询数据库并进行必要的处理显示即可。
案例涉及到数据库，数据库设计如下：
首先创建一个test数据库，内容如下：CREATE TABLE IF NOT EXISTS `province` (
`province_id` int(2) NOT NULL AUTO_INCREMENT,
`province_name` varchar(20) NOT NULL,
PRIMARY KEY (`province_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=3 ;
INSERT INTO `province` (`province_id`, `province_name`) VALUES
(1, '安徽'),
(2, '浙江');
CREATE TABLE IF NOT EXISTS `city` (
`city_id` int(4) NOT NULL AUTO_INCREMENT,
`city_name` varchar(20) NOT NULL,
`province_id` int(4) NOT NULL,
PRIMARY KEY (`city_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=5 ;
INSERT INTO `city` (`city_id`, `city_name`, `province_id`) VALUES
(1, '合肥', 1),
(2, '安庆', 1),
(3, '南京', 2),
(4, '徐州', 2);
CREATE TABLE IF NOT EXISTS `county` (
`county_id` int(4) NOT NULL AUTO_INCREMENT,
`county_name` varchar(20) NOT NULL,
`city_id` int(4) NOT NULL,
PRIMARY KEY (`county_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=5 ;
INSERT INTO `county` (`county_id`, `county_name`, `city_id`) VALUES
(1, '怀宁', 2),
(2, '望江', 2),
(3, '肥东', 1),
(4, '肥西', 1);
对数据库说明：我创建了三张表，分别是省(province)，市(city),县(county),插入了几条测试数据，当然你也可以设计一张表，效率当然没一张表好，所以不建议使用，看你个人习惯。
实现过程并不是很难，思路如下：
1) 初始化所有的省份，这个可以直接从数据库中查询出来省份2)当用户选择省份的时候触发事件，把当前的省份的id通过ajax发出请求传递到服务端的程序中3)服务端根据客户端的请求，查询数据库，并按照一定的格式返回给客户端4)客户端获取服务端的数据，进行必要的处理显示出来
创建select.php(代码简陋，只是实现功能而已，说明原理即可！)1
2
3
4
三级联动(作者：mckee - www.phpddt.com)5
6
7 function createAjax(){
8 var xmlHttp = false;
9 if (window.XMLHttpRequest){
10 xmlHttp = new XMLHttpRequest();
11 }else if(window.ActiveXObject){
12 try{
13 xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
14 }catch(e){
15 try{
16 xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
17 }catch(e){
18 xmlHttp = false;
19 }
20 }
21 }
22 return xmlHttp;
23 }
24
25 var ajax = null;
26 function getCity(province_id){
27 ajax = createAjax();
28 ajax.onreadystatechange=function(){
29 if(ajax.readyState == 4){
30 if(ajax.status == 200){
31 var cities = ajax.responseXML.getElementsByTagName("city");
32 $('city').length = 0;
33 var myoption = document.createElement("option");
34 myoption.value = "";
35 myoption.innerText = "--请选择城市--";
36 $('city').appendChild(myoption);
37 for(var i=0;i
38 var city_id = cities[i].childNodes[0].childNodes[0].nodeValue;
39 var city_name = cities[i].childNodes[1].childNodes[0].nodeValue;
40 var myoption = document.createElement("option");
41 myoption.value = city_id;
42 myoption.innerText = city_name;
43 $('city').appendChild(myoption);
44 }
45 }
46 }
47 }
48
49 ajax.open("post","selectPro.php",true);
50 ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
51 ajax.send("province_id="+province_id);
52
53 }
54
55 function getCounty(city_id){
56 ajax = createAjax();
57 ajax.onreadystatechange=function(){
58 if(ajax.readyState == 4){
59 if(ajax.status == 200){
60
61 var cities = ajax.responseXML.getElementsByTagName("county");
62 $('county').length = 0;
63 var myoption = document.createElement("option");
64 myoption.value = "";
65 myoption.innerText = "--请选择县--";
66 $('county').appendChild(myoption);
67 for(var i=0;i
68 var city_id = cities[i].childNodes[0].childNodes[0].nodeValue;
69 var city_name = cities[i].childNodes[1].childNodes[0].nodeValue;
70 var myoption = document.createElement("option");
71 myoption.value = city_id;
72 myoption.innerText = city_name;
73 $('county').appendChild(myoption);
74 }
75 }
76 }
77 }
78 ajax.open("post","selectPro.php",true);
79 ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
80 ajax.send("city_id="+city_id);
81 }
82
83 function $(id){
84 return document.getElementById(id);
85 }
86
87
88
89
90
91
92 -- 请选择省份--
93 <?php
94 $conn = mysql_connect("localhost","root","");
95 mysql_select_db("test");
96 mysql_query("set names utf8");
97 $sql = "select * from province";
98 $result = mysql_query( $sql );
99 while($res = mysql_fetch_assoc($result)){
100 ?>
101 <?php echo $res['province_name']?>
102 <?php
103 }
104 ?>
105
106
107
108 --请选择城市--
109
110
111
112 --请选择县--
113
114
115
116
创建selectPro.php页面：117 <?php
118 //禁止缓存(www.phpddt.com原创)
119 header("Content-type:text/xml; charset=utf-8");
120 header("Cache-Control:no-cache");
121 //数据库连接
122 $conn = mysql_connect("localhost","root","");
123 mysql_select_db("test");
124 mysql_query("set names utf8");
125
126 if(!empty($_POST['province_id'])){
127
128 $province_id = $_POST['province_id'];
129 $sql = "select * from city where province_id = {$province_id}";
130 $query = mysql_query($sql);
131 $info = "";
132 while($res = mysql_fetch_assoc($query)){
133 $info .= "";
134 $info .= "".$res['city_id']."";
135 $info .= "".$res['city_name']."";
136 $info .= "";
137 }
138 $info .= "";
139 echo $info;
140 }
141
142 if(!empty($_POST['city_id'])){
143
144 $city_id = $_POST['city_id'];
145 $sql = "select * from county where city_id = {$city_id}";
146 $query = mysql_query($sql);
147 $info = "";
148 while($res = mysql_fetch_assoc($query)){
149 $info .= "";
150 $info .= "".$res['county_id']."";
151 $info .= "".$res['county_name']."";
152 $info .= "";
153 }
154 $info .= "";
155 echo $info;
156 }
157 ?>
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