封装类

封装类

(1)可以多个地方调用，避免代码的冗余

(2)安全性高

 1 <?php
 2 class DBDA
 3 {
 4     public $host = "localhost";
 5     public $uid = "root";
 6     public $pwd = "123";
 7     public $dbname = "test_123";
 8     //执行SQL语句返回相应的结果
 9     //$sql 要执行的SQL语句
10     //$type 代表SQL语句的类型，0代表增删改，1代表查询
11     function query($sql,$type=0)
12     {
13         $db = new MySQLi($this->host,$this->uid,$this->pwd,$this->dbname);
14         
15         $result = $db->query($sql);
16         
17         if($type)
18         {
19             //如果是查询，显示数据
20             return $result->fetch_all();
21         }
22         else
23         {
24             //如果是增删改，返回true或者false
25             return $result;
26         }
27     }
28     
29     //返回字符串的方法
30     public function strquery($sql,$type=1)
31     {
32         $db = new MySQLi($this->host,$this->uid,$this->pwd,$this->dbname);
33         $result = $db->query($sql);
34         $arr = $result->fetch_all();
35         $str="";
36         foreach($arr as $v)
37         {
38             $str = $str.implode("^",$v)."|";
39         }
40         
41         $str = substr($str,0,strlen($str)-1);
42         return $str;
43 
44     }
45     
46     //返回JSON
47     function JSONQuery($sql,$type=1)
48     {
49         $db = new MySQLi($this->host,$this->uid,$this->pwd,$this->dbname);
50         $r = $db->query($sql);
51         
52         if($type==1)
53         {
54             return json_encode($r->fetch_all(MYSQLI_ASSOC));
55         }
56         else
57         {
58             return $r;
59         }
60     }
61 }

 

应用

 1 <body>
 2 <select>
 3     <?php
 4     require "DBDA.class.php";//调用
 5     $db = new DBDA(); 
 6     
 7     $sql = "select * from nation";
 8     $arr = $db->query($sql); //此处返回的二维数组，不再是结果集
 9     
10     foreach($arr as $v)
11     {
12         echo "<option value='{$v[0]}'>{$v[1]}</option>";
13     }
14     
15     ?>
16 </select>
17 </body>

 

posted @ 2017-05-02 11:46  ChrissZhao  阅读(177)  评论(0)  编辑  收藏  举报