PHP 常用数据库查询语句

1，php 查询 mysql 并输出多个接口

functionn query(){
    $db = new mysqli('localhost', 'root', '','article');
    $res = $db->query('select id,articledata,c_time from article');
    $arr  = array();
    if($res && is_object($res)){
        while($row = mysqli_fetch_assoc($res)){
            $arr[] = $row;
        }
    }
    print_r(json_encode($arr));
    $db->close();
}