php 链式操作的实现 学习记录

 1 <?php
 2 namespace commom;
 3 
 4 class db
 5 {
 6     public function where($where){
 7         return $this;
 8     }
 9 
10     public function order($order){
11         return $this;
12     }
13 
14     public function limit($limit){
15         return $this;
16     }
17     public function select($select){
18 
19     }
20 }

1 <?php
2 $db  = new DataBase();
3 $db->where()->order()->select();
4 ?>