diff options
Diffstat (limited to 'activerecord/lib/active_record/relation/calculations.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 172 |
1 files changed, 99 insertions, 73 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index ccc14dddeb..c8ebb41131 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -1,5 +1,3 @@ -require 'active_support/deprecation' - module ActiveRecord module Calculations # Count the records. @@ -13,9 +11,33 @@ module ActiveRecord # Person.count(:all) # # => performs a COUNT(*) (:all is an alias for '*') # - # Person.count(:age, distinct: true) + # Person.distinct.count(:age) + # # => counts the number of different age values + # + # If +count+ is used with +group+, it returns a Hash whose keys represent the aggregated column, + # and the values are the respective amounts: + # + # Person.group(:city).count + # # => { 'Rome' => 5, 'Paris' => 3 } + # + # If +count+ is used with +group+ for multiple columns, it returns a Hash whose + # keys are an array containing the individual values of each column and the value + # of each key would be the +count+. + # + # Article.group(:status, :category).count + # # => {["draft", "business"]=>10, ["draft", "technology"]=>4, + # ["published", "business"]=>0, ["published", "technology"]=>2} + # + # If +count+ is used with +select+, it will count the selected columns: + # + # Person.select(:age).count # # => counts the number of different age values + # + # Note: not all valid +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, options = {}) + # TODO: Remove options argument as soon we remove support to + # activerecord-deprecated_finders. column_name, options = nil, column_name if column_name.is_a?(Hash) calculate(:count, column_name, options) end @@ -23,8 +45,10 @@ module ActiveRecord # Calculates the average value on a given column. Returns +nil+ if there's # no row. See +calculate+ for examples with options. # - # Person.average('age') # => 35.8 + # Person.average(:age) # => 35.8 def average(column_name, options = {}) + # TODO: Remove options argument as soon we remove support to + # activerecord-deprecated_finders. calculate(:average, column_name, options) end @@ -32,8 +56,10 @@ module ActiveRecord # with the same data type of the column, or +nil+ if there's no row. See # +calculate+ for examples with options. # - # Person.minimum('age') # => 7 + # Person.minimum(:age) # => 7 def minimum(column_name, options = {}) + # TODO: Remove options argument as soon we remove support to + # activerecord-deprecated_finders. calculate(:minimum, column_name, options) end @@ -41,8 +67,10 @@ module ActiveRecord # with the same data type of the column, or +nil+ if there's no row. See # +calculate+ for examples with options. # - # Person.maximum('age') # => 93 + # Person.maximum(:age) # => 93 def maximum(column_name, options = {}) + # TODO: Remove options argument as soon we remove support to + # activerecord-deprecated_finders. calculate(:maximum, column_name, options) end @@ -50,17 +78,9 @@ module ActiveRecord # with the same data type of the column, 0 if there's no row. See # +calculate+ for examples with options. # - # Person.sum('age') # => 4562 + # Person.sum(:age) # => 4562 def sum(*args) - if block_given? - ActiveSupport::Deprecation.warn( - "Calling #sum with a block is deprecated and will be removed in Rails 4.1. " \ - "If you want to perform sum calculation over the array of elements, use `to_a.sum(&block)`." - ) - self.to_a.sum(*args) {|*block_args| yield(*block_args)} - else - calculate(:sum, *args) - end + calculate(:sum, *args) end # This calculates aggregate values in the given column. Methods for count, sum, average, @@ -78,7 +98,7 @@ module ActiveRecord # puts values["Drake"] # # => 43 # - # drake = Family.find_by_last_name('Drake') + # drake = Family.find_by(last_name: 'Drake') # values = Person.group(:family).maximum(:age) # Person belongs_to :family # puts values[drake] # # => 43 @@ -95,19 +115,17 @@ module ActiveRecord # # Person.sum("2 * age") def calculate(operation, column_name, options = {}) - relation = with_default_scope + # TODO: Remove options argument as soon we remove support to + # activerecord-deprecated_finders. + if column_name.is_a?(Symbol) && attribute_alias?(column_name) + column_name = attribute_alias(column_name) + end - if relation.equal?(self) - if has_include?(column_name) - construct_relation_for_association_calculations.calculate(operation, column_name, options) - else - perform_calculation(operation, column_name, options) - end + if has_include?(column_name) + construct_relation_for_association_calculations.calculate(operation, column_name, options) else - relation.calculate(operation, column_name, options) + perform_calculation(operation, column_name, options) end - rescue ThrowResult - 0 end # Use <tt>pluck</tt> as a shortcut to select one or more attributes without @@ -131,7 +149,7 @@ module ActiveRecord # # SELECT people.id, people.name FROM people # # => [[1, 'David'], [2, 'Jeremy'], [3, 'Jose']] # - # Person.uniq.pluck(:role) + # Person.pluck('DISTINCT role') # # SELECT DISTINCT role FROM people # # => ['admin', 'member', 'guest'] # @@ -145,10 +163,10 @@ module ActiveRecord # def pluck(*column_names) column_names.map! do |column_name| - if column_name.is_a?(Symbol) && self.column_names.include?(column_name.to_s) - "#{connection.quote_table_name(table_name)}.#{connection.quote_column_name(column_name)}" + if column_name.is_a?(Symbol) && attribute_alias?(column_name) + attribute_alias(column_name) else - column_name + column_name.to_s end end @@ -156,24 +174,11 @@ module ActiveRecord construct_relation_for_association_calculations.pluck(*column_names) else relation = spawn - relation.select_values = column_names + relation.select_values = column_names.map { |cn| + columns_hash.key?(cn) ? arel_table[cn] : cn + } result = klass.connection.select_all(relation.arel, nil, bind_values) - columns = result.columns.map do |key| - klass.column_types.fetch(key) { - result.column_types.fetch(key) { - Class.new { def type_cast(v); v; end }.new - } - } - end - - result = result.map do |attributes| - values = klass.initialize_attributes(attributes).values - - columns.zip(values).map do |column, value| - column.type_cast(value) - end - end - columns.one? ? result.map!(&:first) : result + result.cast_values(klass.column_types) end end @@ -188,24 +193,26 @@ module ActiveRecord private def has_include?(column_name) - eager_loading? || (includes_values.present? && (column_name || references_eager_loaded_tables?)) + eager_loading? || (includes_values.present? && ((column_name && column_name != :all) || references_eager_loaded_tables?)) end def perform_calculation(operation, column_name, options = {}) + # TODO: Remove options argument as soon we remove support to + # activerecord-deprecated_finders. operation = operation.to_s.downcase - distinct = options[:distinct] + # If #count is used with #distinct / #uniq it is considered distinct. (eg. relation.distinct.count) + distinct = self.distinct_value if operation == "count" - column_name ||= (select_for_count || :all) + column_name ||= select_for_count unless arel.ast.grep(Arel::Nodes::OuterJoin).empty? distinct = true end column_name = primary_key if column_name == :all && distinct - - distinct = nil if column_name =~ /\s*DISTINCT\s+/i + distinct = nil if column_name =~ /\s*DISTINCT[\s(]+/i end if group_values.any? @@ -229,33 +236,47 @@ module ActiveRecord def execute_simple_calculation(operation, column_name, distinct) #:nodoc: # Postgresql doesn't like ORDER BY when there are no GROUP BY - relation = reorder(nil) + relation = unscope(:order) + + column_alias = column_name + + bind_values = nil if operation == "count" && (relation.limit_value || relation.offset_value) # Shortcut when limit is zero. return 0 if relation.limit_value == 0 query_builder = build_count_subquery(relation, column_name, distinct) + bind_values = query_builder.bind_values + relation.bind_values else column = aggregate_column(column_name) select_value = operation_over_aggregate_column(column, operation, distinct) + column_alias = select_value.alias + column_alias ||= @klass.connection.column_name_for_operation(operation, select_value) relation.select_values = [select_value] query_builder = relation.arel + bind_values = query_builder.bind_values + relation.bind_values end - result = @klass.connection.select_value(query_builder, nil, relation.bind_values) - type_cast_calculated_value(result, column_for(column_name), operation) + result = @klass.connection.select_all(query_builder, nil, bind_values) + row = result.first + value = row && row.values.first + column = result.column_types.fetch(column_alias) do + type_for(column_name) + end + + type_cast_calculated_value(value, column, operation) end def execute_grouped_calculation(operation, column_name, distinct) #:nodoc: group_attrs = group_values if group_attrs.first.respond_to?(:to_sym) - association = @klass.reflect_on_association(group_attrs.first.to_sym) - associated = group_attrs.size == 1 && association && association.macro == :belongs_to # only count belongs_to associations + association = @klass._reflect_on_association(group_attrs.first) + associated = group_attrs.size == 1 && association && association.belongs_to? # only count belongs_to associations group_fields = Array(associated ? association.foreign_key : group_attrs) else group_fields = group_attrs @@ -265,7 +286,7 @@ module ActiveRecord column_alias_for(field) } group_columns = group_aliases.zip(group_fields).map { |aliaz,field| - [aliaz, column_for(field)] + [aliaz, field] } group = group_fields @@ -305,12 +326,17 @@ module ActiveRecord end Hash[calculated_data.map do |row| - key = group_columns.map { |aliaz, column| + key = group_columns.map { |aliaz, col_name| + column = calculated_data.column_types.fetch(aliaz) do + type_for(col_name) + end type_cast_calculated_value(row[aliaz], column) } key = key.first if key.size == 1 key = key_records[key] if associated - [key, type_cast_calculated_value(row[aggregate_alias], column_for(column_name), operation)] + + column_type = calculated_data.column_types.fetch(aggregate_alias) { type_for(column_name) } + [key, type_cast_calculated_value(row[aggregate_alias], column_type, operation)] end] end @@ -336,28 +362,26 @@ module ActiveRecord @klass.connection.table_alias_for(table_name) end - def column_for(field) + def type_for(field) field_name = field.respond_to?(:name) ? field.name.to_s : field.to_s.split('.').last - @klass.columns_hash[field_name] + @klass.type_for_attribute(field_name) end - def type_cast_calculated_value(value, column, operation = nil) + def type_cast_calculated_value(value, type, operation = nil) case operation when 'count' then value.to_i - when 'sum' then type_cast_using_column(value || 0, column) + when 'sum' then type.type_cast_from_database(value || 0) when 'average' then value.respond_to?(:to_d) ? value.to_d : value - else type_cast_using_column(value, column) + else type.type_cast_from_database(value) end end - def type_cast_using_column(value, column) - column ? column.type_cast(value) : value - end - + # TODO: refactor to allow non-string `select_values` (eg. Arel nodes). def select_for_count if select_values.present? - select = select_values.join(", ") - select if select !~ /[,*]/ + select_values.join(", ") + else + :all end end @@ -367,9 +391,11 @@ module ActiveRecord aliased_column = aggregate_column(column_name == :all ? 1 : column_name).as(column_alias) relation.select_values = [aliased_column] - subquery = relation.arel.as(subquery_alias) + arel = relation.arel + subquery = arel.as(subquery_alias) sm = Arel::SelectManager.new relation.engine + sm.bind_values = arel.bind_values select_value = operation_over_aggregate_column(column_alias, 'count', distinct) sm.project(select_value).from(subquery) end |