FOS bundle - How to select users with a specific role?

I am using the FOS bundle and I want to retrieve all users with a given ROLE from the database.

What is the best way to do this?

Just add this in your UserRepository or replace $this->_entityName by YourUserBundle:User:

/**
 * @param string $role
 *
 * @return array
 */
public function findByRole($role)
{
    $qb = $this->_em->createQueryBuilder();
    $qb->select('u')
        ->from($this->_entityName, 'u')
        ->where('u.roles LIKE :roles')
        ->setParameter('roles', '%"'.$role.'"%');

    return $qb->getQuery()->getResult();
}

If you are using FOSUser Groups you should use:

/**
 * @param string $role
 *
 * @return array
 */
public function findByRole($role)
{
    $qb = $this->_em->createQueryBuilder();
    $qb->select('u')
        ->from($this->_entityName, 'u')
        ->leftJoin('u.groups', 'g')
        ->where($qb->expr()->orX(
            $qb->expr()->like('u.roles', ':roles'),
            $qb->expr()->like('g.roles', ':roles')
        ))
        ->setParameter('roles', '%"'.$role.'"%');

    return $qb->getQuery()->getResult();
}