Check that Field Exists with MongoDB

Question

So I'm attempting to find all records who have a fieldset and aren't null.

I try using $exists, however, according to the MongoDB documentation, this query will return fields who equal null.

$exists does match documents that contain the field that stores the null value.

So I'm now assuming I'll have to do something like this:

db.collection.find({ "fieldToCheck" : { $exists : true, $not : null } })

Whenever I try this, however, I get the error [invalid use of $not] Anyone has an idea of how to query for this?

Answer 1

To check that field exists with MongoDB you can use $ne (for "not equal"):-

db.collection.find({ "fieldToCheck": { $exists: true, $ne: null } })