MongoDB.Driver with Cosmos DB array searches

Question

I have an application that was using native mongoDb, we're now pointing it to an Azure Cosmos DB instance, but we're now not getting results when querying arrays.

For example, we have the following customer:

{            
    "email" : "[email protected]",            
    "data" : {                
        "customerGuid" : "a30b5d75ca6241dcbd0260b2516a2165",                                
        "addresses" : [ 
            {                        
                "firstName" : "firstname",
                "lastName" : "lastname",                        
                "postalCode" : "SY1 3VE",                        
            }
        ]
    }
}

And we're using the MongoDB.Driver (via AsQueryable and linq) to find all customers matching on an item in the addresses array

i.e.

var col = db.GetCollection<Customer>("Customer");
var custQuery = col.AsQueryable()
    .Where(c => c.Data.Addresses.Any(a => a.PostalCode == "SY1 3VE"));

But, I am not getting any matches. Digging in further, it seems to be generating a Mongo query that looks like:

{aggregate([{ "$match" : { "data.addresses.postalCode" : "SY1 3VE" } }])}

Which doesn't work for me when I try manually against the database either.

Am I doing something wrong? Or is the Cosmos Mongo Db implementation not fully compatible with the MongoDB.Driver yet?

The query looks good to me. Are you sure you are querying against the right database/collection ? — s7vr
– s7vr, Commented Jun 13, 2017 at 15:36
I am pretty sure. If I run the same thing via roboMongo 0 results, edit it to be aggregate([{ "$match" : { "data.addresses" : {$elemMatch: {"postalCode":"SY1 3VE"}}} }]) It then works! — Vdex
– Vdex, Commented Jun 13, 2017 at 15:40
Single query condition works alike with and without elemMatch operator. docs.mongodb.com/manual/reference/operator/query/elemMatch/… . Can you try in mongo shell ? — s7vr
– s7vr, Commented Jun 13, 2017 at 15:42
This is azure-cosmos DB with a mongo driver, I do know that this works on native mongo, I have one running: Point it there, it works. Point it to azure-cosmos, 0 results for this query. It seems that cosmos db only supports non-array queries — Vdex
– Vdex, Commented Jun 13, 2017 at 15:48
Okay, it simply appears that Cosmo via Mongo, is not ready for productions use. Found another issue, where it treats Aggregate(<condition1>,<condition2>) as ORs, but according to mongo docs it should act like an AND — Vdex
– Vdex, Commented Jun 14, 2017 at 12:37

marc_s · Accepted Answer · 2017-06-26 05:01:38Z

1

Am I doing something wrong? Or is the Cosmos Mongo Db implementation not fully compatible with the MongoDB.Driver yet?

As you mentioned the Cosmos Mongo Db may have not implemented whole commands as native MongoDB. I tried the code you mentioned also get

there is no record returned

But we could use filter to do that, I tested with following code. It works correctly on my side.

 var collection = db.GetCollection<BsonDocument>("BsonDocument");
 var test = collection.Find(Builders <BsonDocument>.Filter.ElemMatch<BsonDocument>("data.addresses",
                    "{\"postalCode\":\"SY1 3VE\"}")).ToList();

Another option:

Based on my experience, it is not recommended, as it will query all of the documents to client.

var col = db.GetCollection<Customer>("Customer");
var custQuery = collection.AsQueryable().ToList().Where(c => c.Data.Addresses.Any(a => a.PostalCode == "SY1 3VE"));

edited Jun 26, 2017 at 5:01

marc_s

760k186 gold badges1.4k silver badges1.5k bronze badges

answered Jun 21, 2017 at 6:14

Tom Sun

24.6k3 gold badges36 silver badges53 bronze badges

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

1 Comment

Vdex Over a year ago

Thanks, I have marked yours as the answer, as I agree that it looks like it is not supported. The "Another choice" would be too heavy in my use case as there will be a lot of records.

Collectives™ on Stack Overflow

MongoDB.Driver with Cosmos DB array searches

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related