3

I have db class that nearly all classes are extending: 

class db {

    protected $db;

    public function __construct() {
        $this->connect();
    }

    protected function connect() {
        $this->db = new MySQLi(db_host, db_user, db_pass, db_name) or die($this->db->error); (line 22)
        $this->db->set_charset('utf8');
    }

}

Here is page class

class page extends db {
    var $common;

    public function __construct() {
        parent::__construct();
        $this->common = new common();

And

class common extends db {

    public function __construct() {
       parent::__construct();
    }

I'm getting

Warning: mysqli::mysqli() [mysqli.mysqli]: (42000/1203): User admin already has more than 'max_user_connections' active connections in /home/tural/public_html/incl/classes/class.db.php on line 22

How can I fix this problem?

Ben
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heron
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  • Do you ever close or pool connections? – Ben Jun 30 '12 at 22:39
  • @Ben no... how can I close it from another class? – heron Jun 30 '12 at 22:40
  • Sorry, mysqli is not my area of expertise; I'm sure someone will be along shortly. In other languages a connection object would also have a `disconnect` function. – Ben Jun 30 '12 at 22:42

2 Answers2

5

Every class inheriting from db you instantiate establishes a new database connection. You should have just one DB class instance. All the page and common don't need to inherit from it, just pass them a db instance.

MaxSem
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0

When you extend db class, a mysqli connection is made after each instance generation. I think it would be better if you define class db as singleton

code is the following ; 

class db {

    private static $_db; // db instance
    protected $connection;

    private function __construct() {
        $this->connection = new MySQLi(db_host, db_user, db_pass, db_name) or die($this->connection->error); 
        $this->connection->set_charset('utf8');
    }

    public function get_instance()
    {
        if( isset( self::$_db) )
        {
           return self::$_db;
        }
        else
        {
           self::$_db = new db();            
        }

        return self::$_db;
    }

}

By this way, you can only create 1 mysql connection.

You can reach db class by db::get_instance()->do_something();

the common class can be like this;

class page  {
    var $common;
    var $db;    

    public function __construct() {
        parent::__construct();
        $this->db = db::get_instance();
        $this->common = new common();
    }
}

I think this is better design.

aacanakin
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  • so, you suggest to remove all extends? and why `$this->db = db::get_instance();` not `$this->db = new db();` ? – heron Jun 30 '12 at 23:04
  • why $this->db = db::get_instance(); not $this->db = new db(); ? – heron Jun 30 '12 at 23:07
  • in singleton pattern, the object type is always static. so, the instance returns are automatically handled to make sure that there exist only 1 instance of that db object. note that in this example, `__construct()` is private so that you can't use `new` statement. – aacanakin Jun 30 '12 at 23:10
  • Getting this error message: ) Parse error: syntax error, unexpected ')', expecting '(' on line if (isset(self::_db)) – heron Jun 30 '12 at 23:25