php设计模式

interface IDatabase
{
//数据库连接操作
public function connect($host, $user, $passwd, $dbname);
//数据库查询
public function query($sql);
//关闭数据库连接
public function close();
}

class MysqliAdapter implements IDatabase { protected $conn;

public function connect($host, $user, $passwd, $dbname)
{
    $conn = mysqli\_connect($host, $user, $passwd, $dbname);
    $this->conn = $conn;
}

public function query($sql)
{
    return mysqli\_query($this->conn, $sql);
}

public function close()
{
    mysqli\_close($this->conn);
}

}

//适配mysql的连接类 class MysqlAdapter implements IDatabase{}

//适配pdo的连接类 class PdoAdapter implements IDatabase{}

$db = new MysqliAdapter(); //适配mysqli //$db = new MysqlAdapter(); //适配mysql //$db = new PdoAdapter(); //适配pdo $db->connect(127.0.0.1, root, 123456, mysql); $res = $db->query("show databases"); $db->close(); var_dump($res);