Calculations now use Arel to construct the query.

Implemented other methods in AR::Base with Arel support.

1 files changed, 86 insertions, 111 deletions

diff --git a/activerecord/lib/active_record/calculations.rb b/activerecord/lib/active_record/calculations.rb
index f077818d3b..9dbfcdf175 100644
--- a/activerecord/lib/active_record/calculations.rb
+++ b/activerecord/lib/active_record/calculations.rb
@@ -54,7 +54,7 @@ module ActiveRecord
       #
       #   Person.average('age') # => 35.8
       def average(column_name, options = {})
-        calculate(:avg, column_name, options)
+        calculate(:average, column_name, options)
       end
 
       # Calculates the minimum value on a given column.  The value is returned
@@ -63,7 +63,7 @@ module ActiveRecord
       #
       #   Person.minimum('age') # => 7
       def minimum(column_name, options = {})
-        calculate(:min, column_name, options)
+        calculate(:minimum, column_name, options)
       end
 
       # Calculates the maximum value on a given column. The value is returned
@@ -72,7 +72,7 @@ module ActiveRecord
       #
       #   Person.maximum('age') # => 93
       def maximum(column_name, options = {})
-        calculate(:max, column_name, options)
+        calculate(:maximum, column_name, options)
       end
 
       # Calculates the sum of values on a given column. The value is returned
@@ -124,19 +124,96 @@ module ActiveRecord
       #   Person.sum("2 * age")
       def calculate(operation, column_name, options = {})
         validate_calculation_options(operation, options)
-        column_name     = options[:select] if options[:select]
-        column_name     = '*' if column_name == :all
-        column          = column_for column_name
+
+        scope = scope(:find)
+
+        merged_includes = merge_includes(scope ? scope[:include] : [], options[:include])
+        joins = construct_join(options[:joins], scope)
+
+        if merged_includes.any?
+          join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(self, merged_includes, joins)
+          joins << join_dependency.join_associations.collect{|join| join.association_join }.join
+        end
+
+        if operation == :count
+          if merged_includes.any?
+            distinct = true
+            column_name = options[:select] || primary_key
+          end
+
+          distinct = nil if column_name.to_s =~ /\s*DISTINCT\s+/i
+          distinct ||= options[:distinct]
+        else
+          distinct = nil
+        end
+
         catch :invalid_query do
+          conditions = construct_conditions(options[:conditions], scope)
+          conditions << construct_limited_ids_condition(conditions, options, join_dependency) if join_dependency && !using_limitable_reflections?(join_dependency.reflections) && ((scope && scope[:limit]) || options[:limit])
+
           if options[:group]
-            return execute_grouped_calculation(operation, column_name, column, options)
+            return execute_grouped_calculation(operation, column_name, options.merge(:merged_conditions => conditions, :merged_joins => joins, :distinct => distinct))
           else
-            return execute_simple_calculation(operation, column_name, column, options)
+            return execute_simple_calculation(operation, column_name, options.merge(:merged_conditions => conditions, :merged_joins => joins, :distinct => distinct))
           end
         end
         0
       end
 
+      def execute_simple_calculation(operation, column_name, options) #:nodoc:
+        table = options[:from] || table_name
+        value = if operation == :count
+          if column_name == :all && options[:select].blank?
+            column_name = "*"
+          elsif !options[:select].blank?
+            column_name = options[:select]
+          end
+          construct_finder_arel(options.merge(:select =>  Arel::Attribute.new(Arel(table), column_name).count(options[:distinct]))).select_value
+        else
+          construct_finder_arel(options.merge(:select =>  Arel::Attribute.new(Arel(table), column_name).send(operation))).select_value
+        end
+
+        type_cast_calculated_value(value, column_for(column_name), operation)
+      end
+
+      def execute_grouped_calculation(operation, column_name, options) #:nodoc:
+        group_attr      = options[:group].to_s
+        association     = reflect_on_association(group_attr.to_sym)
+        associated      = association && association.macro == :belongs_to # only count belongs_to associations
+        group_field     = associated ? association.primary_key_name : group_attr
+        group_alias     = column_alias_for(group_field)
+        group_column    = column_for group_field
+
+        options[:group] = connection.adapter_name == 'FrontBase' ?  group_alias : group_field
+
+        aggregate_alias = column_alias_for(operation, column_name)
+        if operation == :count && column_name == :all
+          options[:select] = "COUNT(*) AS count_all, #{group_field} AS #{group_alias}"
+        else
+          arel_column = Arel::Attribute.new(Arel(table_name), column_name).send(operation)
+          options[:select] = "#{arel_column.as(aggregate_alias).to_sql}, #{group_field} AS #{group_alias}"
+        end
+
+
+        sql = construct_finder_arel(options)
+
+        calculated_data = connection.select_all(sql.to_sql)
+
+        if association
+          key_ids     = calculated_data.collect { |row| row[group_alias] }
+          key_records = association.klass.base_class.find(key_ids)
+          key_records = key_records.inject({}) { |hsh, r| hsh.merge(r.id => r) }
+        end
+
+        calculated_data.inject(ActiveSupport::OrderedHash.new) do |all, row|
+          key   = type_cast_calculated_value(row[group_alias], group_column)
+          key   = key_records[key] if associated
+          value = row[aggregate_alias]
+          all[key] = type_cast_calculated_value(value, column_for(column_name), operation)
+          all
+        end
+      end
+
       protected
         def construct_count_options_from_args(*args)
           options     = {}
@@ -167,108 +244,6 @@ module ActiveRecord
           [column_name || :all, options]
         end
 
-        def construct_calculation_sql(operation, column_name, options) #:nodoc:
-          operation = operation.to_s.downcase
-          options = options.symbolize_keys
-
-          scope           = scope(:find)
-          merged_includes = merge_includes(scope ? scope[:include] : [], options[:include])
-          aggregate_alias = column_alias_for(operation, column_name)
-          column_name     = "#{connection.quote_table_name(table_name)}.#{column_name}" if column_names.include?(column_name.to_s)
-
-          if operation == 'count'
-            if merged_includes.any?
-              options[:distinct] = true
-              column_name = options[:select] || [connection.quote_table_name(table_name), primary_key] * '.'
-            end
-
-            if options[:distinct]
-              use_workaround = !connection.supports_count_distinct?
-            end
-          end
-
-          if options[:distinct] && column_name.to_s !~ /\s*DISTINCT\s+/i
-            distinct = 'DISTINCT ' 
-          end
-          sql = "SELECT #{operation}(#{distinct}#{column_name}) AS #{aggregate_alias}"
-
-          # A (slower) workaround if we're using a backend, like sqlite, that doesn't support COUNT DISTINCT.
-          sql = "SELECT COUNT(*) AS #{aggregate_alias}" if use_workaround
-
-          sql << ", #{options[:group_field]} AS #{options[:group_alias]}" if options[:group]
-          if options[:from]
-            sql << " FROM #{options[:from]} "
-          else
-            sql << " FROM (SELECT #{distinct}#{column_name}" if use_workaround
-            sql << " FROM #{connection.quote_table_name(table_name)} "
-          end
-
-          joins = ""
-          add_joins!(joins, options[:joins], scope)
-
-          if merged_includes.any?
-            join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(self, merged_includes, joins)
-            sql << join_dependency.join_associations.collect{|join| join.association_join }.join
-          end
-
-          sql << joins unless joins.blank?
-
-          add_conditions!(sql, options[:conditions], scope)
-          add_limited_ids_condition!(sql, options, join_dependency) if join_dependency && !using_limitable_reflections?(join_dependency.reflections) && ((scope && scope[:limit]) || options[:limit])
-
-          if options[:group]
-            group_key = connection.adapter_name == 'FrontBase' ?  :group_alias : :group_field
-            sql << " GROUP BY #{options[group_key]} "
-          end
-
-          if options[:group] && options[:having]
-            having = sanitize_sql_for_conditions(options[:having])
-
-            # FrontBase requires identifiers in the HAVING clause and chokes on function calls
-            if connection.adapter_name == 'FrontBase'
-              having.downcase!
-              having.gsub!(/#{operation}\s*\(\s*#{column_name}\s*\)/, aggregate_alias)
-            end
-
-            sql << " HAVING #{having} "
-          end
-
-          sql << " ORDER BY #{options[:order]} "       if options[:order]
-          add_limit!(sql, options, scope)
-          sql << ") #{aggregate_alias}_subquery" if use_workaround
-          sql
-        end
-
-        def execute_simple_calculation(operation, column_name, column, options) #:nodoc:
-          value = connection.select_value(construct_calculation_sql(operation, column_name, options))
-          type_cast_calculated_value(value, column, operation)
-        end
-
-        def execute_grouped_calculation(operation, column_name, column, options) #:nodoc:
-          group_attr      = options[:group].to_s
-          association     = reflect_on_association(group_attr.to_sym)
-          associated      = association && association.macro == :belongs_to # only count belongs_to associations
-          group_field     = associated ? association.primary_key_name : group_attr
-          group_alias     = column_alias_for(group_field)
-          group_column    = column_for group_field
-          sql             = construct_calculation_sql(operation, column_name, options.merge(:group_field => group_field, :group_alias => group_alias))
-          calculated_data = connection.select_all(sql)
-          aggregate_alias = column_alias_for(operation, column_name)
-
-          if association
-            key_ids     = calculated_data.collect { |row| row[group_alias] }
-            key_records = association.klass.base_class.find(key_ids)
-            key_records = key_records.inject({}) { |hsh, r| hsh.merge(r.id => r) }
-          end
-
-          calculated_data.inject(ActiveSupport::OrderedHash.new) do |all, row|
-            key   = type_cast_calculated_value(row[group_alias], group_column)
-            key   = key_records[key] if associated
-            value = row[aggregate_alias]
-            all[key] = type_cast_calculated_value(value, column, operation)
-            all
-          end
-        end
 
       private
         def validate_calculation_options(operation, options = {})
@@ -304,7 +279,7 @@ module ActiveRecord
           case operation
             when 'count' then value.to_i
             when 'sum'   then type_cast_using_column(value || '0', column)
-            when 'avg'   then value && (value.is_a?(Fixnum) ? value.to_f : value).to_d
+            when 'average'   then value && (value.is_a?(Fixnum) ? value.to_f : value).to_d
             else type_cast_using_column(value, column)
           end
         end