MongoDB: Find a document by non-existence of a field?

Question

Is there a way to specify a condition of "where the document doesn't contain a field"?

For example, I want to only find the first of these 2 because it doesn't have the "price" field.

{"fruit":"apple", "color":"red"} 

{"fruit":"banana", "color":"yellow", "price":"2.00"} 

Answer 1

To find a document by non-existence of a field in MongoDB you should try the $exists operator:

db.mycollection.find({ "price" : { "$exists" : false } })