Running "monigoimport --upsert" seems to ignore rows with modifiers in. Perhaps these aren't supported, but it doesn't acknowledge any type of error. In any case, this should definitely be supported!

As an example, the following data file:

{ _id: 1, value: 123 }

{ _id: 2, $set:

{ value: 123 }

}

MongoImport will happily tell me it has "imported 2 objects", but only the one exists. The same happens if the row with _id 2 already exists. It fails silently.

I'm currently writing a ruby script to do this for me... But clearly this should be supported by the provided tools.

Apologies if this has since been fixed but I can't find any relevant tickets in the bug tracker.