symfony2: how to use group_concat in QueryBuilder

Question

I am having nested-set (using Gedmo tree) entity called \"Location\". Entity \"Appartment\" has location_id and what I need to do it to map scalar value called eg \"path\" t

Answer 1

I had similar problem. GROUP_CONCAT does not allow using CASE-WHEN inside. This library fixed my issues, so maybe it will be helpful.

Answer 2

If you want to use it in QueryBuilder you must :

1) add DQL functions GroupConcat: GroupConcat

2 ) Registering GroupConcat :DQL User Defined Functions

another alternative is to use NativeQuery :Native SQL

---

In symfony2 registering a function DQL it's very simple just add GROUP_CONCAT in config.yml like:

    entity_managers:
        default:
            dql:
                string_functions:
                    GROUP_CONCAT: YourBundle\Query\Mysql\GroupConcat

For more information visit Registering Custom DQL Functions

Answer 3

Just an addition to @a.aitboudad's answer:
The DQL function GroupConcat linked appears to have a «limited support for GROUP_CONCAT».
Here is the full support version : The configuration is as he mentioned.

// -------------------------------------------------
// Complete support of GROUP_CONCAT in Doctrine2
// -------------------------------------------------
// Original Article: http://habrahabr.ru/post/181666/
// Automated translation to English: http://sysmagazine.com/posts/181666/ 
// Original github commit: https://github.com/denisvmedia/DoctrineExtensions/blob/d1caf21cd7c71cc557e60c26e9bf25323a194dd1/lib/DoctrineExtensions/Query/Mysql/GroupConcat.php

/**
 * DoctrineExtensions Mysql Function Pack
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to kontakt@beberlei.de so I can send you a copy immediately.
 */

namespace DoctrineExtensions\Query\Mysql;

use Doctrine\ORM\Query\AST\Functions\FunctionNode,
    Doctrine\ORM\Query\Lexer;

/**
 * Full support for:
 *
 * GROUP_CONCAT([DISTINCT] expr [,expr ...]
 *              [ORDER BY {unsigned_integer | col_name | expr}
 *                  [ASC | DESC] [,col_name ...]]
 *              [SEPARATOR str_val])
 *
 */
class GroupConcat extends FunctionNode
{
    public $isDistinct = false;
    public $pathExp = null;
    public $separator = null;
    public $orderBy = null;

    public function parse(\Doctrine\ORM\Query\Parser $parser)
    {
        $parser->match(Lexer::T_IDENTIFIER);
        $parser->match(Lexer::T_OPEN_PARENTHESIS);

        $lexer = $parser->getLexer();
        if ($lexer->isNextToken(Lexer::T_DISTINCT)) {
            $parser->match(Lexer::T_DISTINCT);

            $this->isDistinct = true;
        }

        // first Path Expression is mandatory
        $this->pathExp = array();
        $this->pathExp[] = $parser->SingleValuedPathExpression();

        while ($lexer->isNextToken(Lexer::T_COMMA)) {
            $parser->match(Lexer::T_COMMA);
            $this->pathExp[] = $parser->StringPrimary();
        }

        if ($lexer->isNextToken(Lexer::T_ORDER)) {
            $this->orderBy = $parser->OrderByClause();
        }

        if ($lexer->isNextToken(Lexer::T_IDENTIFIER)) {
            if (strtolower($lexer->lookahead['value']) !== 'separator') {
                $parser->syntaxError('separator');
            }
            $parser->match(Lexer::T_IDENTIFIER);

            $this->separator = $parser->StringPrimary();
        }

        $parser->match(Lexer::T_CLOSE_PARENTHESIS);
    }

    public function getSql(\Doctrine\ORM\Query\SqlWalker $sqlWalker)
    {
        $result = 'GROUP_CONCAT(' . ($this->isDistinct ? 'DISTINCT ' : '');

        $fields = array();
        foreach ($this->pathExp as $pathExp) {
            $fields[] = $pathExp->dispatch($sqlWalker);
        }

        $result .= sprintf('%s', implode(', ', $fields));

        if ($this->orderBy) {
            $result .= ' ' . $sqlWalker->walkOrderByClause($this->orderBy);
        }

        if ($this->separator) {
            $result .= ' SEPARATOR ' . $sqlWalker->walkStringPrimary($this->separator);
        }

        $result .= ')';

        return $result;
    }

}

// -------------------------------------------------
// Example of usage:
// -------------------------------------------------
$query = $this->createQueryBuilder('c')
    ->select("
            c as company,
            GroupConcat(b.id, ';', b.headOffice, ';', b.city, ';', s.name
            ORDER by b.id
            SEPARATOR '|') AS branches
        ")->leftJoin('c.branches', 'b')
    ->leftJoin('b.country', 's')
    ->groupBy('c.id')
    ->setFirstResult(0)
    ->setMaxResults(10)
    ->getQuery();
$result = $query->getResult();

Answer 4

If any comes across this post, there's now a Doctrine Extensions repository in Github. The repo has instructions on how to use it. You can use composer to install it and then use any function you're interested in.

EDIT:

For the Sake of the user Tushar, the way to use GROUP_CONCAT in Doctrine2's DQL is simple install Doctrine Extensions:

composer require beberlei/DoctrineExtensions

To enable it: add the following in your config.yml:

doctrine:
 orm:
     dql:
         string_functions:
             group_concat: DoctrineExtensions\Query\Mysql\GroupConcat

Then in your code, you should be able now to use Group Concat in your DQLs:

$this->createQueryBuilder('location')
            ->select('location')
            ->addSelect("GROUP_CONCAT(DISTINCT location.name SEPARATOR '; ') AS locationNames");

        $result = $queryBuilder->getQuery()->getResult();

Or in the case for the original question:

$query->addSelect("(SELECT GROUP_CONCAT(k99.name ORDER BY k99.level SEPARATOR '$separator') FROM Location k99 WHERE $subquery) AS path");