code: protected function generate()
  	{
  		return
  			'DELETE FROM ' . $this->getPart(CmdDelete::PART_FROM) . ' ' .
  			Assembly::appendWhere($this->getPart(CmdDelete::PART_WHERE), true) .
  			Assembly::appendOrderBy($this->getPart(CmdDelete::PART_ORDER_BY)) .
  			Assembly::append('LIMIT', $this->getPart(CmdDelete::PART_LIMIT));
  	}
docs: Combine all the parts into one sql.
  @return string Created query.