C# aggregate, pagination lookup data structure changes with different pipeline loading approach

[Ruban_Joshva]

Hi,

I am trying to do pagination with c# Mongodb driver. I have a collection called “Account”, from which I am doing lookup to “Contact”. I am having my pipeline stages. when I load the pipeline with appendstage one by one (like below)

    _context.Aggregate().AppendStage<dynamic>(pipeline1).AppendStage(pipeline2).ToList();

it returns the value like this (which is Ok as I want it):

     ["data" : [ { "Account":{account_obj}, "Contact": {contact_obj} },
                     { "Account":{account_obj_2}, "Contact": {contact_obj_2} }],
      "count" : []
     ]

but when I load all pipelines at once like below:

_context.Aggregate<dynamic>(pipelines).ToList();
The value returned turns out to be different like below:
      ["data" : [ { "Account":{account_obj}},
                     { "Account":{account_obj_2} }],
      "count" : [],
      "Contact": null
     ]

like you see the Contact lookup value is coming out of data.

Why is that ? What am I missing here? Any help would be much appreciated. Thanks.

[Ruban_Joshva]

Hi, I have fixed it. Sorry it was my mistake. I was loading the lookup to Contact after facet, now I loaded the lookup stage before facet stage into the pipeline, and it works as expected.