PHP语言 -- Ajax 查询数据

<body><select id="sel"></select><div><br/>
<input type="button" id="btn" value="出现"/></div></body><script type="text/javascript">$(document).ready(function(e){$("#btn").click(function(){$.ajax({url:"chuli.php",
data:{type:2},
type:"POST",
datatype:"TEXT",
success:function(data){

var hang = data.split("|");

var str="";

for(var i=0;i<hang.length;i++)
{
var lie = hang[i].split("^");
str = str+"<option value='"+lie[0]+"'>"+lie[1]+"</option>"
}
$("#sel").html($str);

}});})});</script>

chuli.php

<?php  //不要有空 顶到头写$type=$_POST["type"];include "DBDA.php";$db = new DBDA();switch($type)
{
case 0:$uid = $_POST["u"]; //接收
$pwd = $_POST["p"];$sql = "select count(*) from login where username='{$uid}' and password='{$pwd}'";$attr = $db->Query($sql);if($attr[0][0]==0)
{
echo "用户名密码不正确";
}
else
{
echo "OK";
}break;
case 1:$uid = $_POST["u"];$sql = "select count(*) from login where username='{$uid}'";$attr = $db->Query($sql);if($attr[0][0]==0)
{
echo "OK";
}
else
{
echo "NO";
}break;case 2:
$sql="select * from Nation";$attr = $db->Query($sql); //返回数组  需要转成字符串//n001^汉族|n002^回族|n003^苗族$str="";
for($i=0;$i<count($attr);$i++)
{
for($j=0;$j<count($attr[$i]);$j++)
{
$str=$str.$attr[$i][$i];
$str=$str."^";
}
$str=substr($str,0,strlen($str)-1);
$str=$str."|";
}
$str=substr($str,0,strlen($str)-1);echo "$str";break;
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