Question

What is the correct syntax in MongoDB to return all queries that meet the following criteria:

a % 4 >= 2

I tried using below command, but it returns empty

db.data.find( { a : { $mod : [ 4, { $gte : 2 } ] } } );

Another option would be using Javascript expression as follow:

db.data.find( "this.a % 4 >= 2" );

Javascript expression works and returns expected documents, but it does not work from within PyMongo.

MongoDB version 2.0.4
PyMongo version 2.1.1

Answer 1

I don’t think you can do this currently with a simple query, and you’ll have to use your javascript version instead. You should be able to do that with PyMongo with the where method on the created cursor. F.e.:

cursor = collection.find().where( "this.a % 4 >= 2" );