在PHP中对查询出得数据库数据进行json编码

select.php

<?php
$con = mysql_connect("localhost","Thh","920920thh");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db("my_db", $con);

$result = mysql_query("SELECT * FROM Persons WHERE FirstName = " . "'" . $_POST[firstname] . "'");

$arr=array();

while($row = mysql_fetch_array($result,MYSQL_ASSOC))
  {
      //echo $row['FirstName'] . " " . $row['LastName'] . " " . $row['Age'];
      //echo "<br />";
    $arr[]=$row; 
  }

echo json_encode($arr);

mysql_close($con);
?>

echo出的数据格式如下

[{"id":"43","firstName":"u8c2d","lastName":"u72d7u72d7","age":"18"},{"id":"44","firstName":"u8c2d","lastName":"u55e8","age":"66"}]