i tried something like this in rails with mongoid 3.1.0 and lastest 3.1.3. .limit does not work. below it should return 1 row but it returns all (4)
code:
@go = Gallery.limit(1)
logger.info "count: #{@go.count}"
output:
count: 4
MOPED: 54.234.11.193:10055 QUERY database=mongohqtestdatabase collection=galleries selector= {"$query"=>{}, "$orderby"=>{:_id=>1}} flags=[:slave_ok] limit=-1 skip=0 batch_size=nil fields=nil (276.2010
ms)
which version of mongoid is good with limit() ?
The limit command works fine, but for some reason count ignores the limit. If you cast it to an array you'll see that the limit is working.
Array(Gallery.limit(1)).length # this gives 1
Also, if you actually iterate through the objects you'll see that the limit is working.
As suggested in the official Mongoid answer, we should be using Gallery.limit(1).count(true)
For Mongoid 5 the parameter of CollectionView#count changed :
# Get a count of matching documents in the collection.
#
# @example Get the number of documents in the collection.
# collection_view.count
#
# @param [ Hash ] options Options for the count command.
#
# @option options :skip [ Integer ] The number of documents to skip.
# @option options :hint [ Hash ] Override default index selection and force
# MongoDB to use a specific index for the query.
# @option options :limit [ Integer ] Max number of docs to return.
# @option options :max_time_ms [ Integer ] The maximum amount of time to allow the
# command to run.
#
# @return [ Integer ] The document count.
#
# @since 2.0.0
So you can do something like
collection.count(limit: 1) # => 1
