Forward ActiveRecord::Relation#count to Enumerable#count if block given #24203

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Just for now

@@ -246,9 +246,12 @@ def destroy_all
end
end
- # Count all records using SQL. Construct options and pass them with
- # scope to the target class's +count+.
+ # Returns the number of records. If no arguments are given, it counts all
+ # columns using SQL. If one argument is given, it counts only the passed
+ # column using SQL. If a block is given, it counts the number of records
+ # yielding a true value.
def count(column_name = nil)
+ return super if block_given?
relation = scope
if association_scope.distinct_value
# This is needed because 'SELECT count(DISTINCT *)..' is not valid SQL.
@@ -715,21 +715,27 @@ def distinct
end
alias uniq distinct
- # Count all records using SQL.
+ # Count all records.
#
# class Person < ActiveRecord::Base
# has_many :pets
# end
#
+ # # This will perform the count using SQL.
# person.pets.count # => 3
# person.pets
# # => [
# # #<Pet id: 1, name: "Fancy-Fancy", person_id: 1>,
# # #<Pet id: 2, name: "Spook", person_id: 1>,
# # #<Pet id: 3, name: "Choo-Choo", person_id: 1>
# # ]

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@kaspth

kaspth Mar 19, 2016

Member

This doc also says we're using SQL counting. We should also have an example with a block.

@kaspth

kaspth Mar 19, 2016

Member

This doc also says we're using SQL counting. We should also have an example with a block.

- def count(column_name = nil)
- @association.count(column_name)
+ #
+ # Passing a block will select all of a person's pets in SQL and then
+ # perform the count using Ruby.
+ #
+ # person.pets.count { |pet| pet.name.include?('-') } # => 2
+ def count(column_name = nil, &block)
+ @association.count(column_name, &block)
end
# Returns the size of the collection. If the collection hasn't been loaded,
@@ -37,7 +37,11 @@ module Calculations
# Note: not all valid {Relation#select}[rdoc-ref:QueryMethods#select] expressions are valid #count expressions. The specifics differ
# between databases. In invalid cases, an error from the database is thrown.
def count(column_name = nil)
- calculate(:count, column_name)
+ if block_given?
+ to_a.count { |*block_args| yield(*block_args) }
+ else
+ calculate(:count, column_name)
+ end
end
# Calculates the average value on a given column. Returns +nil+ if there's
@@ -482,6 +482,10 @@ def test_count_with_where_and_order
assert_equal 1, Account.where(firm_name: '37signals').order(:firm_name).reverse_order.count
end
+ def test_count_with_block
+ assert_equal 4, Account.count { |account| account.credit_limit.modulo(10).zero? }
+ end
+
def test_should_sum_expression
# Oracle adapter returns floating point value 636.0 after SUM
if current_adapter?(:OracleAdapter)
@@ -1086,6 +1086,11 @@ def test_count
assert_equal 9, posts.where(:comments_count => 0).count
end
+ def test_count_with_block
+ posts = Post.all
+ assert_equal 10, posts.count { |p| p.comments_count.even? }
+ end
+
def test_count_on_association_relation
author = Author.last
another_author = Author.first