module Mongoid::Contextual::Aggregable::Mongo
Contains behavior for aggregating values in Mongo
.
Public Instance Methods
Get all the aggregate values for the provided field.
@example Get all the aggregate values.
aggregable.aggregates(:likes) # => { # "count" => 2.0, # "max" => 1000.0, # "min" => 500.0, # "sum" => 1500.0, # "avg" => 750.0 # }
@param [ String, Symbol ] field The field name.
@return [ Hash ] count is a number of documents with the provided
field. If there're none, then count is 0 and max, min, sum, avg are nil.
@since 3.0.0
# File lib/mongoid/contextual/aggregable/mongo.rb, line 29 def aggregates(field) result = collection.find.aggregate(pipeline(field), session: _session).to_a if result.empty? { "count" => 0, "sum" => nil, "avg" => nil, "min" => nil, "max" => nil } else result.first end end
Get the average value of the provided field.
@example Get the average of a single field.
aggregable.avg(:likes)
@param [ Symbol ] field The field to average.
@return [ Float ] The average.
@since 3.0.0
# File lib/mongoid/contextual/aggregable/mongo.rb, line 48 def avg(field) aggregates(field)["avg"] end
Get the max value of the provided field. If provided a block, will return the Document
with the greatest value for the field, in accordance with Ruby’s enumerable API.
@example Get the max of a single field.
aggregable.max(:likes)
@example Get the document with the max value.
aggregable.max do |a, b| a.likes <=> b.likes end
@param [ Symbol ] field The field to max.
@return [ Float, Document
] The max value or document with the max
value.
@since 3.0.0
# File lib/mongoid/contextual/aggregable/mongo.rb, line 70 def max(field = nil) block_given? ? super() : aggregates(field)["max"] end
Get the min value of the provided field. If provided a block, will return the Document
with the smallest value for the field, in accordance with Ruby’s enumerable API.
@example Get the min of a single field.
aggregable.min(:likes)
@example Get the document with the min value.
aggregable.min do |a, b| a.likes <=> b.likes end
@param [ Symbol ] field The field to min.
@return [ Float, Document
] The min value or document with the min
value.
@since 3.0.0
# File lib/mongoid/contextual/aggregable/mongo.rb, line 92 def min(field = nil) block_given? ? super() : aggregates(field)["min"] end
Get the sum value of the provided field. If provided a block, will return the sum in accordance with Ruby’s enumerable API.
@example Get the sum of a single field.
aggregable.sum(:likes)
@example Get the sum for the provided block.
aggregable.sum(&:likes)
@param [ Symbol ] field The field to sum.
@return [ Float ] The sum value.
@since 3.0.0
# File lib/mongoid/contextual/aggregable/mongo.rb, line 110 def sum(field = nil) block_given? ? super() : aggregates(field)["sum"] || 0 end
Private Instance Methods
Get the aggregation pipeline for provided field.
@api private
@example Get the pipeline.
aggregable.pipeline(:likes)
@param [ String, Symbol ] field The name of the field.
@return [ Array ] The array of pipeline operators.
@since 3.1.0
# File lib/mongoid/contextual/aggregable/mongo.rb, line 128 def pipeline(field) db_field = "$#{database_field_name(field)}" pipeline = [] pipeline << { "$match" => criteria.exists(field => true).selector } pipeline << { "$sort" => criteria.options[:sort] } if criteria.options[:sort] pipeline << { "$skip" => criteria.options[:skip] } if criteria.options[:skip] pipeline << { "$limit" => criteria.options[:limit] } if criteria.options[:limit] pipeline << { "$group" => { "_id" => field.to_s, "count" => { "$sum" => 1 }, "max" => { "$max" => db_field }, "min" => { "$min" => db_field }, "sum" => { "$sum" => db_field }, "avg" => { "$avg" => db_field } } } end