diff options
Diffstat (limited to 'activerecord/lib/active_record/relation/calculations.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index 31d99f0192..ad49c80e4f 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -16,9 +16,16 @@ module ActiveRecord # # Person.count(:age, distinct: true) # # => counts the number of different age values + # + # Person.where("age > 26").count { |person| gender == 'female' } + # # => queries people where "age > 26" then count the loaded results filtering by gender def count(column_name = nil, options = {}) - column_name, options = nil, column_name if column_name.is_a?(Hash) - calculate(:count, column_name, options) + if block_given? + self.to_a.count { |item| yield item } + else + column_name, options = nil, column_name if column_name.is_a?(Hash) + calculate(:count, column_name, options) + end end # Calculates the average value on a given column. Returns +nil+ if there's @@ -52,9 +59,13 @@ module ActiveRecord # +calculate+ for examples with options. # # Person.sum('age') # => 4562 + # # => returns the total sum of all people's age + # + # Person.where('age > 100').sum { |person| person.age - 100 } + # # queries people where "age > 100" then perform a sum calculation with the block returns def sum(*args) if block_given? - self.to_a.sum(*args) {|*block_args| yield(*block_args)} + self.to_a.sum(*args) { |item| yield item } else calculate(:sum, *args) end @@ -118,7 +129,7 @@ module ActiveRecord # Person.all.map(&:name) # # Pluck returns an <tt>Array</tt> of attribute values type-casted to match - # the plucked column name, if it can be deduced. Plucking a SQL fragment + # the plucked column name, if it can be deduced. Plucking an SQL fragment # returns String values by default. # # Examples: |