MongoDb remove subdocument from document

Question

I have a collection with a following data:

{

  \"_id\" : ObjectId(\"4e3951905e746b3805000000\"),
  \"m\" : \"hello\",
  \"r\" : [{
      \"_id\" : ObjectId(\"4e         


        

Answer 1

It's easy, you just need to use $pull operator:

db.items.update( {}, 
{ $pull : { r : {"_id": ObjectId("4e39519d5e746bc00f000000")} } }, false, false )

Answer 2

dbh.users.update({"_id": ObjectId("4e39519d5e746bc00f000000")}, {"$unset":{"r":1}},False,False)

Try using unset

Reference: MongoDB : Update Modifier semantics of "$unset"