Btukfyl

Can you let me know the C# equivalent of below query please?

db.RolesNPerm.find(

   { "Roles.Name":{$in:[ "PO","role1","TO"] }},

   { _id: 1, ParentId: 1 }

)

I am trying to select the fields(_id and ParentId) in the record if the Name in the embedded document(Roles) matches any of the value in the list.

Here is my MongoDB document

{

    "_id" : "1",

    "ParentId" : "par1",

    "Roles" : [ 

        {

            "Name" : "PO",

            "_id" : "5bc08ee1f12541c3aaa03084"

        }

    ]

}

Below is the result of my query as the Role.Name matches "PO" in the list of names.

{

    "_id" : "1",

    "ParentId" : "par1"

}

There are (at least) two ways to do that:

You can use Builder class to build filter and projection part. The problem is that you can't express Roles.Name part using strongly typed lambda expressions so you can use FieldDefinition type as a fallback

var values = new { "PO", "role1", "TO" };

FieldDefinition<Model, string> field = "Roles.Name";



var filter = Builders<Model>.Filter.In(field, values);

var project = Builders<Model>.Projection.Combine(

        Builders<Model>.Projection.Include(x => x._id),

        Builders<Model>.Projection.Include(x => x.ParentId)

    );



var result = Col.Find(filter).Project(project).ToList();

Alternatively you can use LINQ syntax which will be translated to relevant MongoDB command:

var values = new { "PO", "role1", "TO" };



var q = from doc in Col.AsQueryable()

        where doc.Roles.Any(x => values.Contains(x.Name))

        select new Model6()

        {

            ParentId = doc.ParentId,

            _id = doc._id

        };



var result = q.ToList();