Query for documents where array size is greater than 1

Question

I have a MongoDB collection with documents in the following format:

{
  \"_id\" : ObjectId(\"4e8ae86d08101908e1000001\"),
  \"name\" : [\"Name\"],
  \"zipcod         


        

Answer 1

I found this solution, to find items with an array field greater than certain length

db.allusers.aggregate([
  {$match:{username:{$exists:true}}},
  {$project: { count: { $size:"$locations.lat" }}},
  {$match:{count:{$gt:20}}}
])

The first $match aggregate uses an argument thats true for all the documents. If blank, i would get

"errmsg" : "exception: The argument to $size must be an Array, but was of type: EOO"