/** * @param Select $select * @return string */ public function _renderSelectColumns(Select $select) { $cols = $select->getForcedColumns() ? $select->getForcedColumns() : $select->getAllColumns(); array_walk($cols, function (&$col) { if ($col instanceof Column) { $col = $this->_renderColumnWithAlias($col); } else { if ($col instanceof Token) { $col = $this->_renderToken($col); } } }); $prefix = " "; $separator = ", "; return $prefix . implode($separator, $cols); }