diff options
Diffstat (limited to 'activerecord/lib/active_record/relation/calculations.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index 514ebc2bfe..028e4d80ab 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -19,6 +19,14 @@ module ActiveRecord # # Person.group(:city).count # # => { 'Rome' => 5, 'Paris' => 3 } + # + # 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 databsae is thrown. def count(column_name = nil, options = {}) # TODO: Remove options argument as soon we remove support to # activerecord-deprecated_finders. @@ -168,10 +176,8 @@ module ActiveRecord } end - result = result.map do |attributes| - values = klass.initialize_attributes(attributes).values - - columns.zip(values).map { |column, value| column.type_cast value } + result = result.rows.map do |values| + columns.zip(values).map { |column, value| column.type_cast_from_database value } end columns.one? ? result.map!(&:first) : result end @@ -235,11 +241,14 @@ module ActiveRecord 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) @@ -249,9 +258,10 @@ module ActiveRecord 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 @@ -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.to_sym) + 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 @@ -367,7 +377,7 @@ module ActiveRecord end def type_cast_using_column(value, column) - column ? column.type_cast(value) : value + column ? column.type_cast_from_database(value) : value end # TODO: refactor to allow non-string `select_values` (eg. Arel nodes). @@ -385,9 +395,11 @@ 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 |