mongodb - Mongo field A greater than field B

Question

i'm trying a simple query in Mongo which in MySQL would look like this.

select * from emails where bounceCount > sentCount;

So far I have.

db.email.find({ bounceCount : { $gt : sentCount } } );

But I get this error

JS Error: ReferenceError: sentCount is not defined (shell):0

How do I reference the sentCount in that shell?

Answer 1

It should do the trick:

db.emails.find({ $expr: { $gt: [ "$bounceCount" , "$sentCount" ] } });

Here is the reference where I found it: https://docs.mongodb.com/manual/reference/operator/query/expr/#op._S_expr