<?php

class Database {
    private $sql;

    public function where($where) {
        $this->sql .= " where {$where}";
        return $this;
    }

    public function order($order) {
        $this->sql .= " order by {$order}";
        return $this;
    }

    public function limit($limit) {
        $this->sql .= " limit ({$limit})";
        return $this;
    }

    public function go() {
        return $this->sql;
    }
}

$db = new Database();
$stmt = $db->where(‘id=1 and name=2‘)->order(‘id DESC‘)->limit(10)->go();

?>