private function buildWhere(array $cols, $search)
{
$qb = $this->_repository->createQueryBuilder('e');
$or = $qb->expr()->orx();
foreach (array_keys($cols) as $i => $property) {
if (!is_string($property)) {
// not searchable
continue;
}
$or->add($qb->expr()->like("e.{$property}", $qb->expr()->literal("%{$search}%")));
}
return $or;
}