public function db($dbName) {
		if (!$this->isOpen) return;
		$this->db=$dbName;
		$this->conn1->select_db($dbName);
	}
public function db($dbName) {
		if (!$this->isOpen) return;
		$this->db=$dbName;
		$this->conn1->select_db($dbName);
	}
public function db ( $ dbName ) { if ( ! $ this -> isOpen ) return ; $ this -> db = $ dbName ; $ this -> conn1 -> select_db ( $ dbName ) ; }
It changes default database.
@param $dbName
@test void this('travisdb')
It changes default database .