private static void handleSubQueries(Client client, Select select) throws SqlParseException {
if (select.containsSubQueries()) {
for (SubQueryExpression subQueryExpression : select.getSubQueries()) {
QueryAction queryAction = handleSelect(client, subQueryExpression.getSelect());
executeAndFillSubQuery(client, subQueryExpression, queryAction);
}
}
}
private static void executeAndFillSubQuery(
Client client, SubQueryExpression subQueryExpression, QueryAction queryAction)
throws SqlParseException {
List<Object> values = new ArrayList<>();
Object queryResult;
try {
queryResult = QueryActionElasticExecutor.executeAnyAction(client, queryAction);
} catch (Exception e) {
throw new SqlParseException("could not execute SubQuery: " + e.getMessage());
}
String returnField = subQueryExpression.getReturnField();
if (queryResult instanceof SearchHits) {
SearchHits hits = (SearchHits) queryResult;
for (SearchHit hit : hits) {
values.add(ElasticResultHandler.getFieldValue(hit, returnField));
}
} else {
throw new SqlParseException(
"on sub queries only support queries that return Hits and not aggregations");
}
subQueryExpression.setValues(values.toArray());
}