php7ではmysqlが使えません

php5:
<?php
    header("content-type:text/html;charset=utf-8");
    error_reporting(E_ALL ^ E_DEPRECATED);
    $link = mysql_connect("127.0.0.1","root","123456");
    mysql_select_db("shunyi",$link);
    mysql_query("set names utf8");
    $point = "select * from sy_location";
    $rest = mysql_query($point);
    $arr = array();
    while($re = mysql_fetch_assoc($rest)){
        array_push($arr, $re);
    }
    echo json_encode($arr);
?>

php7:
<?php
    header("content-type:text/html;charset=utf-8");
    error_reporting(E_ALL ^ E_DEPRECATED);
    $link = mysqli_connect("127.0.0.1","root","123456","shunyi");
    $point = "select * from sy_location";
    $rest = mysqli_query($link,$point);
    $arr = array();
    while($re = mysqli_fetch_assoc($rest)){
        array_push($arr, $re);
    }
    echo json_encode($arr);
?>