链接mysql数据库，输出数据

<?PHP

//  旧版的

header("Content-type: text/html; charset=utf-8");
$con = mysql_connect('localhost', 'root', '');
mysql_select_db('music');
mysql_query('set names utf8');
$sql = 'select name, musicName from music_list';
$query = mysql_query($sql);
if( $query && mysql_num_rows($query) ){
while($row = mysql_fetch_assoc($query)){
$data[] = $row;
}
echo json_encode($data);
}

//下面是5.3以上的版本的
//定义头文件utf-8编码
header("Content-type: text/html; charset=utf-8");
//链接数据库
$link = new mysqli('localhost', 'root', '', 'music');
//如果数据库链接失败
if(mysqli_connect_errno()){
die('Unable to connect!');
}
//对数据库定于utf8的编码
mysqli_set_charset($link, 'utf8');
//表查询语句
$sql = 'select name, musicName from music_list';
//执行查询代码
$result = $link->query($sql);
//声明data数组变量
$data = array();
//循环查询语句  放到data数组里面
while( $row = $result->fetch_object() ){
$data[] = $row;
}
//输出数组
echo json_encode($data);
?>