-- 数据库: `student`---- ------------------------------------------------------------ 表的结构 `student`--CREATE TABLE `student` ( `id` int(50) NOT NULL auto_increment, `name` varchar(50) collate utf8_unicode_ci NOT NULL, `dept` varchar(50) collate utf8_unicode_ci NOT NULL, `class` varchar(50) collate utf8_unicode_ci NOT NULL, `sex` varchar(50) collate utf8_unicode_ci NOT NULL, `dept_id` int(50) NOT NULL, `class_id` int(50) NOT NULL, PRIMARY KEY (`id`)) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=5 ;---- 导出表中的数据 `student`--INSERT INTO `student` (`id`, `name`, `dept`, `class`, `sex`, `dept_id`, `class_id`) VALUES(1, '计算机名字', '计算机工程系', '计061', '男', 1, 11),(2, '教计名字', '计算机工程系', '教技061', '男', 1, 14),(3, '管理名字', '管理系', '管理061', '女', 2, 21),(4, '机械名字', '机械工程系', '自动化061', '男', 3, 31);
<?php$link=mysql_connect("localhost","root","") or die("数据库服务器连接错误".mysql_error());mysql_select_db("student",$link) or die("数据库访问错误".mysql_error());mysql_query("set character set gb2312");mysql_query("set names gb2312");?><html> <head> <title>下拉框连动</title> </head><body><script language="JavaScript">//二级菜单数组var subcat = new Array();<?php$i=0;$sql="select * from student";$query=mysql_query($sql,$link);while($arr=mysql_fetch_array($query)){ echo "subcat[".$i++."] = new Array('".$arr["dept_id"]."','".$arr["class"]."','".$arr["class_id"]."');/n";}?>//三级菜单数组var subcat2 = new Array();<?php$i=0;$sql="select * from student";$query=mysql_query($sql,$link);while($arr=mysql_fetch_array($query)){ echo "subcat2[".$i++."] = new Array('".$arr["class_id"]."','".$arr["class"]."','".$arr["name"]."');/n";}?>function changeselect1(locationid){ document.form1.s2.length = 0; document.form1.s2.options[0] = new Option('22请选择22',''); for (i=0; i<subcat.length; i++) { if (subcat[i][0] == locationid) { document.form1.s2.options[document.form1.s2.length] = new Option(subcat[i][1], subcat[i][2]); } }}function changeselect2(locationid){ document.form1.s3.length = 0; document.form1.s3.options[0] = new Option('33请选择33',''); for (i=0; i<subcat2.length; i++) { if (subcat2[i][0] == locationid) { document.form1.s3.options[document.form1.s3.length] = new Option(subcat2[i][2], subcat2[i][0]); } }}</script>三级联动演示：<BR><form name="form1"><select name="s1" onChange="changeselect1(this.value)"><option>--请选择--</option><option value=1>计算机工程系</option><option value=2>管理系</option><option value=3>机械工程系</option></select><select name="s2" onChange="changeselect2(this.value)"> <option>--请选择--</option></select><select name="s3"> <option>--请选择--</option></select></form></body></html> 
