How to find into mongodb to the last item of an array?

Question

I want to find documents where last elements in an array equals to some value. Array elements may be accessed by specific array position:

// i.e. comments[0]         


        

Answer 1

I am not sure why my answer above is deleted. I am reposting it. I am pretty sure without changing the schema, you should be able to do it this way.

db.example.find({ "comments:{$slice:-1}.by" : "Abe" } 

// ... or

db.example.find({ "comments.by" : "Abe" }

This by default takes the last element in the array.