Mongodb find() query : return only unique values (

问题:

This question already has an answer here:

• Get distinct records values 5 answers

I have a collection of documents :

{
    "networkID": "myNetwork1",
    "pointID": "point001",
    "param": "param1"
}
{
    "networkID": "myNetwork2",
    "pointID": "point002",
    "param": "param2"
}
{
    "networkID": "myNetwork1",
    "pointID": "point003",
    "param": "param3"
}
...

pointIDs are unique but networkIDs are not.

Is it possible to query Mongodb in such a way that the result will be : [myNetwork1,myNetwork2]

right now I only managed to return [myNetwork1,myNetwork2,myNetwork1]

I need a list of unique networkIDs to populate an autocomplete select2 component. As I may have up to 50K documents I would prefer mongoDb to filter the results at the query level.

回答1:

I think you can use db.collection.distinct(fields,query)

You will be able to get the distinct values in your case for NetworkID.

It should be something like this :

Db.collection.distinct('NetworkID')