如何在 OOPS 中的 php mysql 中断开或关闭与 DB 的数据库连接

Question

Consider 3 classes DBCONNECT , book , new

class dbconnect {
    protected $db_conn;
    public $db_user='xxxx';
    public $db_pass='xxxx';
    public $db_host='localhost';
    public $db_name='xxxx';

function connect() {
        try{
            $this->db_conn=new PDO("mysql:host=$this->db_host;dbname=$this->db_name",$this->db_user,$this->db_pass);
            return $this->db_conn;
        }
        catch (Exception $e){
            return $e->getMessage();
        }
    }
}


include_once ( 'class.dbconn.php' );

class Book{
    public $link;

    public function __construct(){
        $db_conn=new dbconnect();
        $this->link = $db_conn->connect();
        return $this->link;
    }
}

class new{
include_once 'classes/class.book.php';
$book = new Book();
}

everything works fine there were no errors in my code but I have a doubt of closing the connection to my database. Is it mandatory to close a connection? If it's mandatory, then how do I close the connection and in which class I need to write the code?

Answer 1

It's not mandatory to close the connection manually. PHP will handle that on it's own. If you want to manually close it you can use $this->db_conn = null;

public function disconnect() {
    $this->db_conn = null
}

If you want to be a perfectionist, you could also do this, although not necessary

public function __destruct() {
    $this->disconnect();
}

Answer 2

your new code

<?php
class dbconnect {
    protected $db_conn;
    public $db_user='xxxx';
    public $db_pass='xxxx';
    public $db_host='localhost';
    public $db_name='xxxx';

function connect() {
        try{
            $this->db_conn=new PDO("mysql:host=$this->db_host;dbname=$this->db_name",$this->db_user,$this->db_pass);
            return $this->db_conn;
        }
        catch (Exception $e){
            return $e->getMessage();
        }
    }

function disconnect()
    {
            try
            {
                $this->db_conn=null;
                return $this->db_conn;
            }
            catch (Exception $e){
                return $e->getMessage();
            }
            }
    }
}


include_once ( 'class.dbconn.php' );

class Book{
    public $link;

    public function __construct(){
        $db_conn=new dbconnect();
        $this->link = $db_conn->connect();
        return $this->link;
    }
}

class new{
include_once 'classes/class.book.php';
$book = new Book();

$close = new dbconnect();
// this will close connection
$close->disconnect();


}?>

one more thing is you can create constructor and destructor.