Mongodb select all fields group by one field and sort by another field

Question

We have collection \'message\' with following fields

_id |   messageId |  chainId | createOn

1   |       1     |    A     | 155
2   |       2     |    A     | 1         


        

Answer 1

here is the solution using springframework.data.mongodb:

Aggregation aggregation = Aggregation.newAggregation(
                Aggregation.group("chainId"),
                Aggregation.sort(new Sort(Sort.Direction.ASC, "createdOn"))
              );
AggregationResults results = mongoTemplate.aggregate(aggregation, "collection_name", XxxBean.class);