B4J Question Aggregate command in mongodb

[lucdrb]

Hi

I would like to use the distinct command from Mongodb in B4J but I can't find How To:

Syntax in mongoDb is

db.collection.distinct(field, query, options)

It Finds the distinct values for a specified field across a single collection or view and returns the results in an array.

Help would be welcome
Thanks in advance

Luc

 

[Erel]

I will add it next week.

 

[lucdrb]

Many thanks

Luc

 

[Erel]

It is very simple to find distinct values with the aggregate method:

Data:

Dim collection As MongoCollection = db.GetCollection("test")
collection.Insert(Array(CreateMap("value": 100), CreateMap("value": 200), CreateMap("value": 200)))

Find distinct values of value field:

For Each m As Map In collection.Aggregate(Array(CreateMap("$group": CreateMap("_id": "$value"))))
       Log(m.Get("_id"))
   Next

 

[lucdrb]

Thanks Erel,

This week-end I've found that the distinct command exist as a database command.
As I think that if it's possible to make it from the database side it would be better, I used it with the RunCommand (Command As Map) As Map
Of the MongoDatabase from the JmongoDB library.

But I'll be very gratefull to have the same RunCommand for all the collections methods (https://docs.mongodb.com/manual/reference/method/js-collection/).

Annyway, thanks you for all that you've allready made.

Luc

 

[Erel]

As I think that if it's possible to make it from the database side it would be better

The aggregate commands are executed on the server, not on the client.

 

[lucdrb]

The aggregate commands are executed on the server, not on the client.

You're right my mistake.