MongoDB aggregation Spring/Java (project with array, group and match)

Question

I'm having trouble to write that query in Java using springframework.

db.getCollection('fish').aggregate(
        {$match : {"uploadDate" : { $gte : new ISODate("2017-05-22T00:00:00Z"), $lte : new ISODate("2017-05-25T00:00:00Z") }}},
        {$group: {_id: {lake : "$lake", type : "$type"}, count: {$sum: 1}}} ,
        {$project: {array : ["$_id.type" , "$count"], count : "$count"}},
        {$group: {_id: {lake : "$_id.lake"}, count: {$sum: 1}, types : {$addToSet : "$array"}}})

I was able to write match and group but I'm having trouble to add project that has array containing both id.type and count. So far I was able to write this

Aggregation aggregation = newAggregation(match(Criteria.where("uploadDate").gte(created).lte(newCreatedDate)),
        group("lake").count().as("values"));

I couldn't find any solution how to write it and I only see that you can add Fields/Strings to project().

s7vr · Accepted Answer · 2017-05-24 22:44:47Z

1

I'll give you the alternative as there is really no way to create the expressions the way you want.

You have to use AggregationOperation and use BasicDBObject to create the project stage.

Something like

AggregationOperation project = aggregationOperationContext -> new BasicDBObject("$project", new BasicDBObject("array", Arrays.asList("$_id.type" , "$count")).append("count", "$count"));

answered May 24, 2017 at 22:44

s7vr

76.2k12 gold badges118 silver badges135 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

lukaszrys Over a year ago

Thanks alot. With your solution I can even mix two approches

George Z. · Accepted Answer · 2019-10-11 23:44:22Z

0

I agree with the solution given by user2683814 but not sure solution was not working. But by using org.bson.Document instead of BasicDBObject fixed the issue, so thought to share.

AggregationOperation project = aggregationOperationContext -> new Document("$project", new Document("array", Arrays.asList("$_id.type" , "$count")).append("count", "$count"));

edited Oct 11, 2019 at 23:44

George Z.

6,8594 gold badges33 silver badges53 bronze badges

answered Oct 11, 2019 at 19:36

letsDoThis

711 silver badge7 bronze badges

Collectives™ on Stack Overflow

MongoDB aggregation Spring/Java (project with array, group and match)

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related