What is returned from Mongoose query that finds no matches?

Question

I\'m a little confused reading the Mongoose documentation.

If I run a query in mongoose which matches no documents in the collection, what are the values of err

Answer 1

If conditions were valid but no matches were found:

• find: err is null, result is []

• findOne and findById: err is null, result is null

However, if some condition was invalid (e.g. field is string but you pass an object, or you pass an invalid _id)

For all three: err is {..}, result is undefined

Answer 2

It depends on the query. If it is a find, then results == []. If it is a findOne, then results == null. No errors if everything else is ok.