Question

Consider the following MongoDB document:

SomeObject {
    nested_objects_ids : [
        ObjectId( "1..." ), 
        ObjectId( "2..." ),
        ...
        ObjectId( "N..." )
    ]
}

The length of nested_object_ids is not limited.
Is there an elegant way to keep the nested_object_ids array sorted after pushing arbitrary values (i.e. ObjectIds)?

Thank you!

Answer 1

Is there an elegant way to keep the nested_object_ids array sorted after pushing arbitrary values?

Unfortunately, there is nothing I would consider “elegant”.

The $push command does not work here. Your only option is to pull the entire sub-array into the client and then re-write it with a $set.

Honestly, when it comes to dealing with “arrays of objects”, MongoDB has limited functionality. You can update with $push, $pull and you can index on an object field, but that’s about it.

It’s difficult to update a specific sub-object. And querying doesn’t return the sub-object, but instead returns the whole document. You could filter it down to returning nested_object_ids, but you always get the whole set there.

A question for you: why do the nested objects need to be sorted?