protected function prepareSearch(Request $request)
    {
        $value = $request->getSearch()->getValue();

        if (!empty($value)) {
            $where = [];
            foreach ($request->getColumns() as $column) {
                if ($column->getSearchable() === true) {
                    $where[$column->getData() . ' LIKE'] = '%' . $value . '%';
                }
            }

            $this->query->andWhere(
                function (QueryExpression $exp) use ($where) {
                    return $exp->or_($where);
                }
            );
        }
    }