MongoDB: Can’t canonicalize query: BadValue Projection cannot have a mix of inclusion and exclusion

You cannot mix inclusion and exclusion, the only exception is the _id field.

For example if you have this:

{
   "_id": ObjectId("53d1fd30bdcf7d52c0d217de"),
   "name": "bill",
   "birthdate": ISODate("2014-07-80T00:00:00.000Z"),
   "created": ISODate("2014-07-25T06:44:38.641Z")
}

If all you want is the “name” and “birthdate” you need to do this:

db.collection.find({},{ "_id": 0, "name": 1, "birthdate": 1 })

Or this:

db.collection.find({},{ "_id": 0, "created": 0 })

But it is not allowed to “mix” any other operations other than “_id”

db.collection.find({},{ "_id": 0, "name": 1, "created": 0 })

That would also produce an error.

This is all covered in the manual pages.