diff options
Diffstat (limited to 'activerecord/lib/active_record/relation/calculations.rb')
-rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 68 |
1 files changed, 38 insertions, 30 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index 45ffb99868..c8ebb41131 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -19,6 +19,22 @@ module ActiveRecord # # 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. @@ -162,18 +178,7 @@ module ActiveRecord 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) { result.identity_type } - } - end - - result = result.map do |attributes| - values = klass.initialize_attributes(attributes).values - - columns.zip(values).map { |column, value| column.type_cast value } - end - columns.one? ? result.map!(&:first) : result + result.cast_values(klass.column_types) end end @@ -188,7 +193,7 @@ 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 = {}) @@ -231,31 +236,36 @@ 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_all(query_builder, nil, relation.bind_values) + 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 - column_for(column_name) + type_for(column_name) end type_cast_calculated_value(value, column, operation) @@ -265,8 +275,8 @@ module ActiveRecord 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 @@ -318,14 +328,14 @@ module ActiveRecord Hash[calculated_data.map do |row| key = group_columns.map { |aliaz, col_name| column = calculated_data.column_types.fetch(aliaz) do - column_for(col_name) + 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 - column_type = calculated_data.column_types.fetch(aggregate_alias) { column_for(column_name) } + 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 @@ -352,24 +362,20 @@ 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? @@ -385,9 +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 |