我如何在春季编写查询聚合Mongo？ 我究竟做错了什么？

Question

I've got an aggregation query in MongoDB that works when I run it directly in the shell. Here's the shell query:

db.game.aggregate([
 {$unwind: "$array"}, 
 {$group:{"_id" : "$array.ToId", "pointCount": {$sum:"$array.point"}}}, 
 {$project: {_id: 0, "ToId":"$_id", "pointCount": 1}}
 ])

I want to receive

List<Map<String, Integer>>

Where String = ToId, Integer = pointCount

That's what I'm doing

@Inject
private MongoTemplate mongoTemplate;

public List<Map<String, Integer>> getUsers(A array) {

    Aggregation aggregation = newAggregation(
        unwind("achievement"),
        group("_id", "array.ToId", "pointCount").sum("array.PointCount"),
        project("ToId", "pointCount")
    );

    AggregationResults groupResults = mongoTemplate.aggregate(
        aggregation, UserRepo.class, A.class);

    List<Map<String, Integer>> users = groupResults.getMappedResults();

    return users;
}

But it gives an error: Cannot resolve method 'newAggregation(org.springframework.data.mongodb.core.aggregation.UnwindOperation, org.springframework.data.mongodb.core.aggregation.GroupOperation.GroupOperationBuilder, org.springframework.data.mongodb.core.aggregation.ProjectionOperation)'

What am I doing wrong, please explain. Thank you

Answer 1

Spring aggregation code doesn't match mongo shell query. I've provided answer to fix the compilation error. You're missing alias for sum operation.

Aggregation aggregation = newAggregation(
            unwind("achievement"),
            group("_id", "array.ToId", "pointCount").sum("array.PointCount").as("pointCount"),
            project("ToId", "pointCount"));