<?php

abstract class DbConnection
{
    protected $link;  
    protected $result;
    protected $numRows;

    abstract public function query($q);
    abstract public function next();
    abstract public function getLastId();
    abstract public function closeConnection();
    abstract public function cloneConnection();
    abstract public function escape($string, $quoted = true);
    abstract public function startTransaction();
    abstract public function commit();
    abstract public function rollBack();
    
    public function getLink() {
	return $this->link;
    }
	
    public function getRowsNum() {
	return $this->numRows;
    }
	
    public function queryFirstRowCol($q) {
	$row = $this->queryFirstRow($q);
	return current($row);
    }  
	
   public function queryFirstColumnSet($q) {
		$arr = array();
		$this->query($q);
		while($row = $this->next())
			$arr[] = current($row);
		return $arr;
	}
	
	public function queryResultArr($q) {
		$arr = array();
		$this->query($q);
		while($row = $this->next())
			$arr[] = $row;
		return $arr;
	}
	
	public function queryFirstRow($q) {
		$this->query($q);
                $row = $this->next();
                if(!$row) throw new NoResultException($q);
		return $row;
	}
}

?>