php设计模式——适配器模式

适配器模式

• 适配器模式(Adapter）模式：将一个类的接口，转换成客户期望的另一个类的接口。适配器让原本接口不兼容的类可以合作无间。列如：将数据库接口封装成一样的接口， 这样就可以适用于不同场景

• 案例 将php数据操作封装成统一的api

  • 统一接口api

    <?php
    namespace Test;
    
    interface IDatabase
      {
            function connect($host, $user, $passwd, $dbname);
            function query($sql);
            function close();
      }
    

  • mysql 连接

  
  <?php
   namespace Test;
   class MySQL implements IDatabase
  {
            protected $conn;
            function connect($host, $user, $passwd, $dbname)
            {
                    $conn = mysql_connect($host, $user, $passwd);
                    mysql_select_db($dbname, $conn);
                  $this->conn = $conn;
            }
  
          function query($sql)
          {
              $res = mysql_query($sql, $this->conn);
              return $res;
          }
  
        function close()
        {
                mysql_close($this->conn);
        }
  }
  

• mysqli 连接

<?php
namespace TEST;
class MySQLi implements IDatabase
{
    protected $conn;

    function connect($host, $user, $passwd, $dbname)
    {
        $conn = mysqli_connect($host, $user, $passwd, $dbname);
        $this->conn = $conn;
    }

    function query($sql)
    {
        return mysqli_query($this->conn, $sql);
    }

    function close()
    {
        mysqli_close($this->conn);
    }
}

• PDO连接

<?php
namespace Test;
class PDO implements IDatabase
{
    protected $conn;
    function connect($host, $user, $passwd, $dbname)
    {
        $conn = new \PDO("mysql:host=$host;dbname=$dbname", $user, $passwd);
        $this->conn = $conn;
    }

    function query($sql)
    {
        return $this->conn->query($sql);
    }

    function close()
    {
        unset($this->conn);
    }
}