MongoDb query array with null values

Question

I have objects in my collection that look like:

{ MyArray:[null, \"some value\", null] }

I want to query those objects that have a null value a

Answer 1

Ok, I figured it out by loading my "null" candidates via my C# driver and it turns out that the values are not null, but Bson Undefined!! They are displayed as "null" in the shell! See http://jira.mongodb.org/browse/SERVER-2426. This works:

db.xxx.find({"Attrs":{$type:6}})