concat example

            array_shift( $this->stack );
        }
        else {
            array_shift( $this->stack );
        }

        $this->current_namespace = false;
    }

    function concat (&$str1, $str2="") {
        if (!isset($str1) ) {
            $str1="";
        }
        $str1 .= $str2;
    }

    function append_content($text) {
        if ( $this->initem ) {
            $this->concat( $this->current_item[ $this->incontent ], $text );
        }
        elseif ( $this->inchannel ) {
            

break;

                case 'add':
                    $builder->set("{$prefix}.$column", $builder->expr()->sum("{$prefix}.$column", $operationValue));
                    break;

                case 'subtract':
                    $builder->set("{$prefix}.$column", $builder->expr()->diff("{$prefix}.$column", $operationValue));
                    break;

                case 'append':
                    $builder->set("{$prefix}.$column", $builder->expr()->concat("{$prefix}.$column", $operationValue));
                    break;

                case 'prepend':
                    $builder->set("{$prefix}.$column", $builder->expr()->concat($operationValue, "{$prefix}.$column"));
                    break;

                case 'dql':
                    // This is quite limited, as many sql features are not supported. Also the update-statements                     // are limited to the current entity, so you will not be able to set a product's name                     // to its details number because the detail cannot be joined here.                     $builder->set("{$prefix}.$column", new Literal($operation['value']));