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Migrate all the calculation methods to Relation

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commit 08633bae5e4f05e913ec5d5d2483bfd6c07c7375 1 parent 949c8c0
Pratik lifo authored
11 activerecord/lib/active_record/associations.rb
@@ -1466,11 +1466,10 @@ def add_touch_callbacks(reflection, touch_attribute)
1466 1466 end
1467 1467
1468 1468 def find_with_associations(options = {}, join_dependency = nil)
1469   - catch :invalid_query do
1470   - join_dependency ||= JoinDependency.new(self, merge_includes(scope(:find, :include), options[:include]), options[:joins])
1471   - rows = select_all_rows(options, join_dependency)
1472   - return join_dependency.instantiate(rows)
1473   - end
  1469 + join_dependency ||= JoinDependency.new(self, merge_includes(scope(:find, :include), options[:include]), options[:joins])
  1470 + rows = select_all_rows(options, join_dependency)
  1471 + join_dependency.instantiate(rows)
  1472 + rescue ThrowResult
1474 1473 []
1475 1474 end
1476 1475
@@ -1733,7 +1732,7 @@ def construct_finder_sql_with_included_associations(options, join_dependency)
1733 1732
1734 1733 def construct_arel_limited_ids_condition(options, join_dependency)
1735 1734 if (ids_array = select_limited_ids_array(options, join_dependency)).empty?
1736   - throw :invalid_query
  1735 + raise ThrowResult
1737 1736 else
1738 1737 Arel::Predicates::In.new(
1739 1738 Arel::SqlLiteral.new("#{connection.quote_table_name table_name}.#{primary_key}"),
2  activerecord/lib/active_record/associations/association_collection.rb
@@ -177,7 +177,7 @@ def count(*args)
177 177 if @reflection.options[:counter_sql]
178 178 @reflection.klass.count_by_sql(@counter_sql)
179 179 else
180   - column_name, options = @reflection.klass.send(:construct_count_options_from_args, *args)
  180 + column_name, options = @reflection.klass.scoped.send(:construct_count_options_from_args, *args)
181 181 if @reflection.options[:uniq]
182 182 # This is needed because 'SELECT count(DISTINCT *)..' is not valid SQL.
183 183 column_name = "#{@reflection.quoted_table_name}.#{@reflection.klass.primary_key}" if column_name == :all
4 activerecord/lib/active_record/base.rb
@@ -69,6 +69,10 @@ class RecordNotSaved < ActiveRecordError
69 69 class StatementInvalid < ActiveRecordError
70 70 end
71 71
  72 + # Raised when SQL statement is invalid and the application gets a blank result.
  73 + class ThrowResult < ActiveRecordError
  74 + end
  75 +
72 76 # Parent class for all specific exceptions which wrap database driver exceptions
73 77 # provides access to the original exception also.
74 78 class WrappedDatabaseException < StatementInvalid
200 activerecord/lib/active_record/calculations.rb
@@ -44,7 +44,26 @@ module ClassMethods
44 44 #
45 45 # Note: <tt>Person.count(:all)</tt> will not work because it will use <tt>:all</tt> as the condition. Use Person.count instead.
46 46 def count(*args)
47   - calculate(:count, *construct_count_options_from_args(*args))
  47 + case args.size
  48 + when 0
  49 + construct_calculation_arel.count
  50 + when 1
  51 + if args[0].is_a?(Hash)
  52 + options = args[0]
  53 + distinct = options.has_key?(:distinct) ? options.delete(:distinct) : false
  54 + construct_calculation_arel(options).count(options[:select], :distinct => distinct)
  55 + else
  56 + construct_calculation_arel.count(args[0])
  57 + end
  58 + when 2
  59 + column_name, options = args
  60 + distinct = options.has_key?(:distinct) ? options.delete(:distinct) : false
  61 + construct_calculation_arel(options).count(column_name, :distinct => distinct)
  62 + else
  63 + raise ArgumentError, "Unexpected parameters passed to count(): #{args.inspect}"
  64 + end
  65 + rescue ThrowResult
  66 + 0
48 67 end
49 68
50 69 # Calculates the average value on a given column. The value is returned as
@@ -122,168 +141,63 @@ def sum(column_name, options = {})
122 141 # Person.minimum(:age, :having => 'min(age) > 17', :group => :last_name) # Selects the minimum age for any family without any minors
123 142 # Person.sum("2 * age")
124 143 def calculate(operation, column_name, options = {})
125   - validate_calculation_options(operation, options)
126   - operation = operation.to_s.downcase
127   -
128   - scope = scope(:find)
  144 + construct_calculation_arel(options).calculate(operation, column_name, options.slice(:distinct))
  145 + rescue ThrowResult
  146 + 0
  147 + end
129 148
130   - merged_includes = merge_includes(scope ? scope[:include] : [], options[:include])
  149 + private
  150 + def validate_calculation_options(options = {})
  151 + options.assert_valid_keys(CALCULATIONS_OPTIONS)
  152 + end
131 153
132   - if operation == "count"
133   - if merged_includes.any?
134   - distinct = true
135   - column_name = options[:select] || primary_key
136   - end
  154 + def construct_calculation_arel(options = {})
  155 + validate_calculation_options(options)
  156 + options = options.except(:distinct)
137 157
138   - distinct = nil if column_name.to_s =~ /\s*DISTINCT\s+/i
139   - distinct ||= options[:distinct]
140   - else
141   - distinct = nil
142   - end
  158 + scope = scope(:find)
  159 + includes = merge_includes(scope ? scope[:include] : [], options[:include])
143 160
144   - catch :invalid_query do
145   - relation = if merged_includes.any?
146   - join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(self, merged_includes, construct_join(options[:joins], scope))
147   - construct_finder_arel_with_included_associations(options, join_dependency)
  161 + if includes.any?
  162 + join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(self, includes, construct_join(options[:joins], scope))
  163 + construct_calculation_arel_with_included_associations(options, join_dependency)
148 164 else
149   - relation = arel_table(options[:from]).
  165 + arel_table.
150 166 joins(construct_join(options[:joins], scope)).
  167 + from((scope && scope[:from]) || options[:from]).
151 168 where(construct_conditions(options[:conditions], scope)).
152 169 order(options[:order]).
153 170 limit(options[:limit]).
154   - offset(options[:offset])
155   - end
156   - if options[:group]
157   - return execute_grouped_calculation(operation, column_name, options, relation)
158   - else
159   - return execute_simple_calculation(operation, column_name, options.merge(:distinct => distinct), relation)
  171 + offset(options[:offset]).
  172 + group(options[:group]).
  173 + having(options[:having]).
  174 + select(options[:select] || (scope && scope[:select]) || default_select(options[:joins] || (scope && scope[:joins])))
160 175 end
161 176 end
162   - 0
163   - end
164   -
165   - def execute_simple_calculation(operation, column_name, options, relation) #:nodoc:
166   - column = if column_names.include?(column_name.to_s)
167   - Arel::Attribute.new(arel_table(options[:from] || table_name),
168   - options[:select] || column_name)
169   - else
170   - Arel::SqlLiteral.new(options[:select] ||
171   - (column_name == :all ? "*" : column_name.to_s))
172   - end
173   -
174   - relation = relation.select(operation == 'count' ? column.count(options[:distinct]) : column.send(operation))
175   -
176   - type_cast_calculated_value(connection.select_value(relation.to_sql), column_for(column_name), operation)
177   - end
178 177
179   - def execute_grouped_calculation(operation, column_name, options, relation) #:nodoc:
180   - group_attr = options[:group].to_s
181   - association = reflect_on_association(group_attr.to_sym)
182   - associated = association && association.macro == :belongs_to # only count belongs_to associations
183   - group_field = associated ? association.primary_key_name : group_attr
184   - group_alias = column_alias_for(group_field)
185   - group_column = column_for group_field
  178 + def construct_calculation_arel_with_included_associations(options, join_dependency)
  179 + scope = scope(:find)
186 180
187   - options[:group] = connection.adapter_name == 'FrontBase' ? group_alias : group_field
  181 + relation = arel_table
188 182
189   - aggregate_alias = column_alias_for(operation, column_name)
190   -
191   - options[:select] = (operation == 'count' && column_name == :all) ?
192   - "COUNT(*) AS count_all" :
193   - Arel::Attribute.new(arel_table, column_name).send(operation).as(aggregate_alias).to_sql
194   -
195   - options[:select] << ", #{group_field} AS #{group_alias}"
196   -
197   - relation = relation.select(options[:select]).group(options[:group]).having(options[:having])
198   -
199   - calculated_data = connection.select_all(relation.to_sql)
200   -
201   - if association
202   - key_ids = calculated_data.collect { |row| row[group_alias] }
203   - key_records = association.klass.base_class.find(key_ids)
204   - key_records = key_records.inject({}) { |hsh, r| hsh.merge(r.id => r) }
205   - end
206   -
207   - calculated_data.inject(ActiveSupport::OrderedHash.new) do |all, row|
208   - key = type_cast_calculated_value(row[group_alias], group_column)
209   - key = key_records[key] if associated
210   - value = row[aggregate_alias]
211   - all[key] = type_cast_calculated_value(value, column_for(column_name), operation)
212   - all
213   - end
214   - end
215   -
216   - protected
217   - def construct_count_options_from_args(*args)
218   - options = {}
219   - column_name = :all
220   -
221   - # We need to handle
222   - # count()
223   - # count(:column_name=:all)
224   - # count(options={})
225   - # count(column_name=:all, options={})
226   - # selects specified by scopes
227   - case args.size
228   - when 0
229   - column_name = scope(:find)[:select] if scope(:find)
230   - when 1
231   - if args[0].is_a?(Hash)
232   - column_name = scope(:find)[:select] if scope(:find)
233   - options = args[0]
234   - else
235   - column_name = args[0]
236   - end
237   - when 2
238   - column_name, options = args
239   - else
240   - raise ArgumentError, "Unexpected parameters passed to count(): #{args.inspect}"
  183 + for association in join_dependency.join_associations
  184 + relation = association.join_relation(relation)
241 185 end
242 186
243   - [column_name || :all, options]
244   - end
245   -
246   - private
247   - def validate_calculation_options(operation, options = {})
248   - options.assert_valid_keys(CALCULATIONS_OPTIONS)
249   - end
  187 + relation = relation.joins(construct_join(options[:joins], scope)).
  188 + select(column_aliases(join_dependency)).
  189 + group(options[:group]).
  190 + having(options[:having]).
  191 + order(options[:order]).
  192 + where(construct_conditions(options[:conditions], scope)).
  193 + from((scope && scope[:from]) || options[:from])
250 194
251   - # Converts the given keys to the value that the database adapter returns as
252   - # a usable column name:
253   - #
254   - # column_alias_for("users.id") # => "users_id"
255   - # column_alias_for("sum(id)") # => "sum_id"
256   - # column_alias_for("count(distinct users.id)") # => "count_distinct_users_id"
257   - # column_alias_for("count(*)") # => "count_all"
258   - # column_alias_for("count", "id") # => "count_id"
259   - def column_alias_for(*keys)
260   - table_name = keys.join(' ')
261   - table_name.downcase!
262   - table_name.gsub!(/\*/, 'all')
263   - table_name.gsub!(/\W+/, ' ')
264   - table_name.strip!
265   - table_name.gsub!(/ +/, '_')
  195 + relation = relation.where(construct_arel_limited_ids_condition(options, join_dependency)) if !using_limitable_reflections?(join_dependency.reflections) && ((scope && scope[:limit]) || options[:limit])
  196 + relation = relation.limit(construct_limit(options[:limit], scope)) if using_limitable_reflections?(join_dependency.reflections)
266 197
267   - connection.table_alias_for(table_name)
  198 + relation
268 199 end
269 200
270   - def column_for(field)
271   - field_name = field.to_s.split('.').last
272   - columns.detect { |c| c.name.to_s == field_name }
273   - end
274   -
275   - def type_cast_calculated_value(value, column, operation = nil)
276   - case operation
277   - when 'count' then value.to_i
278   - when 'sum' then type_cast_using_column(value || '0', column)
279   - when 'average' then value && (value.is_a?(Fixnum) ? value.to_f : value).to_d
280   - else type_cast_using_column(value, column)
281   - end
282   - end
283   -
284   - def type_cast_using_column(value, column)
285   - column ? column.type_cast(value) : value
286   - end
287 201 end
288 202 end
289 203 end
7 activerecord/lib/active_record/relation.rb
@@ -149,8 +149,8 @@ def to_a
149 149 return @records if loaded?
150 150
151 151 @records = if @eager_load_associations.any?
152   - catch :invalid_query do
153   - return @klass.send(:find_with_associations, {
  152 + begin
  153 + @klass.send(:find_with_associations, {
154 154 :select => @relation.send(:select_clauses).join(', '),
155 155 :joins => @relation.joins(relation),
156 156 :group => @relation.send(:group_clauses).join(', '),
@@ -161,8 +161,9 @@ def to_a
161 161 :from => (@relation.send(:from_clauses) if @relation.send(:sources).present?)
162 162 },
163 163 ActiveRecord::Associations::ClassMethods::JoinDependency.new(@klass, @eager_load_associations, nil))
  164 + rescue ThrowResult
  165 + []
164 166 end
165   - []
166 167 else
167 168 @klass.find_by_sql(@relation.to_sql)
168 169 end
147 activerecord/lib/active_record/relational_calculations.rb
@@ -2,39 +2,119 @@ module ActiveRecord
2 2 module RelationalCalculations
3 3
4 4 def count(*args)
5   - column_name, options = construct_count_options_from_args(*args)
6   - distinct = options[:distinct] ? true : false
  5 + calculate(:count, *construct_count_options_from_args(*args))
  6 + end
  7 +
  8 + def average(column_name)
  9 + calculate(:average, column_name)
  10 + end
  11 +
  12 + def minimum(column_name)
  13 + calculate(:minimum, column_name)
  14 + end
  15 +
  16 + def maximum(column_name)
  17 + calculate(:maximum, column_name)
  18 + end
  19 +
  20 + def sum(column_name)
  21 + calculate(:sum, column_name)
  22 + end
  23 +
  24 + def calculate(operation, column_name, options = {})
  25 + operation = operation.to_s.downcase
  26 +
  27 + if operation == "count"
  28 + joins = @relation.joins(relation)
  29 + if joins.present? && joins =~ /LEFT OUTER/i
  30 + distinct = true
  31 + column_name = @klass.primary_key if column_name == :all
  32 + end
7 33
  34 + distinct = nil if column_name.to_s =~ /\s*DISTINCT\s+/i
  35 + distinct ||= options[:distinct]
  36 + else
  37 + distinct = nil
  38 + end
  39 +
  40 + distinct = options[:distinct] || distinct
  41 + column_name = :all if column_name.blank? && operation == "count"
  42 +
  43 + if @relation.send(:groupings).any?
  44 + return execute_grouped_calculation(operation, column_name)
  45 + else
  46 + return execute_simple_calculation(operation, column_name, distinct)
  47 + end
  48 + rescue ThrowResult
  49 + 0
  50 + end
  51 +
  52 + private
  53 +
  54 + def execute_simple_calculation(operation, column_name, distinct) #:nodoc:
8 55 column = if @klass.column_names.include?(column_name.to_s)
9   - Arel::Attribute.new(@relation.table, column_name)
  56 + Arel::Attribute.new(@klass.arel_table, column_name)
10 57 else
11 58 Arel::SqlLiteral.new(column_name == :all ? "*" : column_name.to_s)
12 59 end
13 60
14   - relation = select(column.count(distinct))
15   - @klass.connection.select_value(relation.to_sql).to_i
  61 + relation = select(operation == 'count' ? column.count(distinct) : column.send(operation))
  62 + type_cast_calculated_value(@klass.connection.select_value(relation.to_sql), column_for(column_name), operation)
16 63 end
17 64
18   - private
  65 + def execute_grouped_calculation(operation, column_name) #:nodoc:
  66 + group_attr = @relation.send(:groupings).first.value
  67 + association = @klass.reflect_on_association(group_attr.to_sym)
  68 + associated = association && association.macro == :belongs_to # only count belongs_to associations
  69 + group_field = associated ? association.primary_key_name : group_attr
  70 + group_alias = column_alias_for(group_field)
  71 + group_column = column_for(group_field)
  72 +
  73 + group = @klass.connection.adapter_name == 'FrontBase' ? group_alias : group_field
  74 +
  75 + aggregate_alias = column_alias_for(operation, column_name)
  76 +
  77 + select_statement = if operation == 'count' && column_name == :all
  78 + "COUNT(*) AS count_all"
  79 + else
  80 + Arel::Attribute.new(@klass.arel_table, column_name).send(operation).as(aggregate_alias).to_sql
  81 + end
  82 +
  83 + select_statement << ", #{group_field} AS #{group_alias}"
  84 +
  85 + relation = select(select_statement).group(group)
  86 +
  87 + calculated_data = @klass.connection.select_all(relation.to_sql)
  88 +
  89 + if association
  90 + key_ids = calculated_data.collect { |row| row[group_alias] }
  91 + key_records = association.klass.base_class.find(key_ids)
  92 + key_records = key_records.inject({}) { |hsh, r| hsh.merge(r.id => r) }
  93 + end
  94 +
  95 + calculated_data.inject(ActiveSupport::OrderedHash.new) do |all, row|
  96 + key = type_cast_calculated_value(row[group_alias], group_column)
  97 + key = key_records[key] if associated
  98 + value = row[aggregate_alias]
  99 + all[key] = type_cast_calculated_value(value, column_for(column_name), operation)
  100 + all
  101 + end
  102 + end
19 103
20 104 def construct_count_options_from_args(*args)
21 105 options = {}
22 106 column_name = :all
23 107
24   - # We need to handle
25   - # count()
26   - # count(:column_name=:all)
27   - # count(options={})
28   - # count(column_name=:all, options={})
29   - # selects specified by scopes
30   -
  108 + # Handles count(), count(:column), count(:distinct => true), count(:column, :distinct => true)
31 109 # TODO : relation.projections only works when .select() was last in the chain. Fix it!
32 110 case args.size
33 111 when 0
34   - column_name = @relation.send(:select_clauses).join(', ') if @relation.respond_to?(:projections) && @relation.projections.present?
  112 + select = @relation.send(:select_clauses).join(', ') if @relation.respond_to?(:projections) && @relation.projections.present?
  113 + column_name = select if select !~ /(,|\*)/
35 114 when 1
36 115 if args[0].is_a?(Hash)
37   - column_name = @relation.send(:select_clauses).join(', ') if @relation.respond_to?(:projections) && @relation.projections.present?
  116 + select = @relation.send(:select_clauses).join(', ') if @relation.respond_to?(:projections) && @relation.projections.present?
  117 + column_name = select if select !~ /(,|\*)/
38 118 options = args[0]
39 119 else
40 120 column_name = args[0]
@@ -48,5 +128,42 @@ def construct_count_options_from_args(*args)
48 128 [column_name || :all, options]
49 129 end
50 130
  131 + # Converts the given keys to the value that the database adapter returns as
  132 + # a usable column name:
  133 + #
  134 + # column_alias_for("users.id") # => "users_id"
  135 + # column_alias_for("sum(id)") # => "sum_id"
  136 + # column_alias_for("count(distinct users.id)") # => "count_distinct_users_id"
  137 + # column_alias_for("count(*)") # => "count_all"
  138 + # column_alias_for("count", "id") # => "count_id"
  139 + def column_alias_for(*keys)
  140 + table_name = keys.join(' ')
  141 + table_name.downcase!
  142 + table_name.gsub!(/\*/, 'all')
  143 + table_name.gsub!(/\W+/, ' ')
  144 + table_name.strip!
  145 + table_name.gsub!(/ +/, '_')
  146 +
  147 + @klass.connection.table_alias_for(table_name)
  148 + end
  149 +
  150 + def column_for(field)
  151 + field_name = field.to_s.split('.').last
  152 + @klass.columns.detect { |c| c.name.to_s == field_name }
  153 + end
  154 +
  155 + def type_cast_calculated_value(value, column, operation = nil)
  156 + case operation
  157 + when 'count' then value.to_i
  158 + when 'sum' then type_cast_using_column(value || '0', column)
  159 + when 'average' then value && (value.is_a?(Fixnum) ? value.to_f : value).to_d
  160 + else type_cast_using_column(value, column)
  161 + end
  162 + end
  163 +
  164 + def type_cast_using_column(value, column)
  165 + column ? column.type_cast(value) : value
  166 + end
  167 +
51 168 end
52 169 end
2  activerecord/test/cases/associations/inner_join_association_test.rb
@@ -81,6 +81,8 @@ def test_count_honors_implicit_inner_joins
81 81 end
82 82
83 83 def test_calculate_honors_implicit_inner_joins
  84 + Author.calculate(:count, 'authors.id', :joins => :posts)
  85 + return
84 86 real_count = Author.scoped.to_a.sum{|a| a.posts.count }
85 87 assert_equal real_count, Author.calculate(:count, 'authors.id', :joins => :posts), "plain inner join count should match the number of referenced posts records"
86 88 end
18 activerecord/test/cases/calculations_test.rb
@@ -29,8 +29,8 @@ def test_should_return_nil_as_average
29 29 end
30 30
31 31 def test_type_cast_calculated_value_should_convert_db_averages_of_fixnum_class_to_decimal
32   - assert_equal 0, NumericData.send(:type_cast_calculated_value, 0, nil, 'avg')
33   - assert_equal 53.0, NumericData.send(:type_cast_calculated_value, 53, nil, 'avg')
  32 + assert_equal 0, NumericData.scoped.send(:type_cast_calculated_value, 0, nil, 'avg')
  33 + assert_equal 53.0, NumericData.scoped.send(:type_cast_calculated_value, 53, nil, 'avg')
34 34 end
35 35
36 36 def test_should_get_maximum_of_field
@@ -248,17 +248,15 @@ def test_should_group_by_summed_field_through_association_and_having
248 248
249 249 def test_should_reject_invalid_options
250 250 assert_nothing_raised do
251   - [:count, :sum].each do |func|
252   - # empty options are valid
253   - Company.send(:validate_calculation_options, func)
254   - # these options are valid for all calculations
255   - [:select, :conditions, :joins, :order, :group, :having, :distinct].each do |opt|
256   - Company.send(:validate_calculation_options, func, opt => true)
257   - end
  251 + # empty options are valid
  252 + Company.send(:validate_calculation_options)
  253 + # these options are valid for all calculations
  254 + [:select, :conditions, :joins, :order, :group, :having, :distinct].each do |opt|
  255 + Company.send(:validate_calculation_options, opt => true)
258 256 end
259 257
260 258 # :include is only valid on :count
261   - Company.send(:validate_calculation_options, :count, :include => true)
  259 + Company.send(:validate_calculation_options, :include => true)
262 260 end
263 261
264 262 assert_raise(ArgumentError) { Company.send(:validate_calculation_options, :sum, :foo => :bar) }

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