Convert ObjectID to String in mongo Aggregation

Question

I\'m in this scenario right now: I have a collection X:

{
  _id:ObjectId(\'56edbb4d5f084a51131dd4c6\'),
  userRef:ObjectId(\'56edbb4d5f084a51131dd4c6\'),
  seria         


        

Answer 1

I think you may try to resolve it by using an Array which contains both fields:

{$project:{newkey:['$userRef','$serialNumber']},{$match:{newkey:{$in:filterArray}}}}

this may match the data with both fields to the filter. Please notice that the data in the newkey array should have the same data type with the filterArray elements.