如何截断symfony 3中的表？

I want to truncate table in symfony 3.0

I am using following approach.

create Entity:User.php

Create Repository : UserRepository.php

/**
 * UserRepository 
 */

namespace UserBundle\Entity;

use Doctrine\ORM\EntityRepository;


class UserRepository extends EntityRepository {

    public function truncateTable() {
        $em = $this->getEntityManager();
        $dql = 'TRUNCATE TABLE UserBundle:User';
        $query = $em->createQuery($dql);

        return $query->getResult();
    }

}

When i am trying to run this code from controller: I am getting following message:

[2/2] QueryException: [Syntax Error] line 0, col 0: Error: Expected SELECT, UPDATE or DELETE, got 'TRUNCATE'

Anyone can suggest me ?

The code below should help you

    $classMetaData = $em->getClassMetadata($className);
    $connection = $em->getConnection();
    $dbPlatform = $connection->getDatabasePlatform();
    $connection->beginTransaction();
    try {
        $connection->query('SET FOREIGN_KEY_CHECKS=0');
        $q = $dbPlatform->getTruncateTableSql($classMetaData->getTableName());
        $connection->executeUpdate($q);
        $connection->query('SET FOREIGN_KEY_CHECKS=1');
        $connection->commit();
    }
    catch (\Exception $e) {
        $connection->rollback();
    }