protected function _buildSQL()
	{
		if( $this->_stmt !== null ) {
			return $this->_stmt;
		}

		$i = 1;
		foreach( $this->_parts as $part )
		{
			$this->_stmt .= $part;
			if( isset( $this->_binds[$i] ) ) {
				$this->_stmt .= $this->_binds[$i];
			}
			$i++;
		}

		return $this->_stmt;
	}