Mongotemplate aggregation with condition

Question

I have a collection where the documents look like this:

{
  _id: "545b9fa0dd5318a4285f7ce7",
  owner: "admin",  
  messages: [
    {
      id: "100",
      status: "sent",
      note: ""
    },
    {
      id: "100",
      status: "pending",
      note: ""
    },
    {
      id: "101",
      status: "sent",
      note: ""
    },
    {
      id: "102",
      status: "sent",
      note: ""
    },
    {
      id: "101",
      status: "done",
      note: ""
    }
  ]
}

(This is just a short example, in my case a large array of array)

I need to request the assembly and get some statistics for a specific document. So in this example, if I request a doucment with the id: "545b9fa0dd5318a4285f7ce7" I should get this result:

{
   sent: 3,
   pending: 1,
   done: 1
}

How can I do this aggregation using spring mongotemplate?

Answer 1

$cond . Spring MongoDB , , $group , $project.

$cond :

https://jira.spring.io/browse/DATAMONGO-861

:

db.collection.aggregate([
    { "$match": { "_id": ObjectId("545b9fa0dd5318a4285f7ce7") } },
    { "$unwind": "$messages" },
    { "$group": {
        "_id": "$_id",
        "sent": {
            "$sum": {
                "$cond": [
                    { "$eq": [ "$mesages.status", "sent" ] },
                    1,
                    0
                ]
            }
        },
        "pending": {
            "$sum": {
                "$cond": [
                    { "$eq": [ "$messages.status", "pending" ] },
                    1,
                    0
                ]
            }
        },
        "done": {
            "$sum": {
                "$cond": [
                    { "$eq": [ "$messages.status", "done" ] },
                    1,
                    0
                ]
            }
        }
    }}
])

​​ mongotemplate, , , DBObject:

public class CustomGroupOperation implements AggregationOperation {
    private DBObject operation;

    public CustomGroupOperation (DBObject operation) {
        this.operation = operation;
    }

    @Override
    public DBObject toDBObject(AggregationOperationContext context) {
        return context.getMappedObject(operation);
    }
}

"$ group" DBObject :

   DBObject myGroup = (DBObject)new BasicDBObject(
        "$group", new BasicDBObject(
            "_id","$_id"
        ).append(
            "sent", new BasicDBObject(
                "$sum", new BasicDBObject(
                    "$cond", new Object[]{
                        new BasicDBObject(
                            "$eq", new Object[]{ "$messages.status", "sent"}
                        ),
                        1,
                        0
                    }
                )
            )
        ).append(
            "pending", new BasicDBObject(
                "$sum", new BasicDBObject(
                    "$cond", new Object[]{
                        new BasicDBObject(
                            "$eq", new Object[]{ "$messages.status", "pending"}
                        ),
                        1,
                        0
                    }
                )
             )
        ).append(
            "done", new BasicDBObject(
                "$sum", new BasicDBObject(
                    "$cond", new Object[]{
                         new BasicDBObject(
                            "$eq", new Object[]{ "$messages.status", "done"}
                         ),
                         1,
                         0
                    }
                 )
            )
        )
     );


   ObjectId myId = new ObjectId("545b9fa0dd5318a4285f7ce7");

   Aggregation aggregation = newAggregation(
           match(Criteria.where("_id").is(myId)),
           unwind("messges"),
           new CustomGroupOperation(myGroup)
   );

, .

, , , , AgggregationOperation DBObject .

Answer 2

:

db.collection.aggregate(
    { $match : { "_id" : ObjectId("545b9fa0dd5318a4285f7ce7") } },
    { $unwind : "$messages" },
    { $group : { "_id" : "$messages.status", "count" : { $sum : 1} } }
)

status, message , status count 0.