/**
* GROUP BY clause
*
* @param RequestInterface $request
* @param QueryInterface $query
*/
protected function clauseGroupBy(RequestInterface $request, QueryInterface $query)
{
$groupBy = [];
foreach ($request->getGroupBy() as $value) {
$groupBy[] = $this->identifierToString($value, $query);
}
if ($groupBy) {
$query->appendClause(static::CLAUSE_GROUP_BY, implode(static::LIST_SEPARATOR, $groupBy));
}
}
