diff options
Diffstat (limited to 'activerecord/lib/active_record/relation.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation.rb | 317 |
1 files changed, 186 insertions, 131 deletions
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb index 0df895eb67..daafb0b645 100644 --- a/activerecord/lib/active_record/relation.rb +++ b/activerecord/lib/active_record/relation.rb @@ -1,34 +1,32 @@ # -*- coding: utf-8 -*- +require 'arel/collectors/bind' module ActiveRecord # = Active Record Relation class Relation - JoinOperation = Struct.new(:relation, :join_class, :on) - MULTI_VALUE_METHODS = [:includes, :eager_load, :preload, :select, :group, :order, :joins, :where, :having, :bind, :references, - :extending] + :extending, :unscope] SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :from, :reordering, - :reverse_order, :uniq, :create_with] + :reverse_order, :distinct, :create_with, :uniq] + INVALID_METHODS_FOR_DELETE_ALL = [:limit, :distinct, :offset, :group, :having] VALUE_METHODS = MULTI_VALUE_METHODS + SINGLE_VALUE_METHODS include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation attr_reader :table, :klass, :loaded - attr_accessor :default_scoped alias :model :klass alias :loaded? :loaded - alias :default_scoped? :default_scoped def initialize(klass, table, values = {}) - @klass = klass - @table = table - @values = values - @implicit_readonly = nil - @loaded = false - @default_scoped = false + @klass = klass + @table = table + @values = values + @offsets = {} + @loaded = false + @predicate_builder = PredicateBuilder.new(klass, table) end def initialize_copy(other) @@ -39,7 +37,7 @@ module ActiveRecord reset end - def insert(values) + def insert(values) # :nodoc: primary_key_value = nil if primary_key && Hash === values @@ -56,16 +54,7 @@ module ActiveRecord im = arel.create_insert im.into @table - conn = @klass.connection - - substitutes = values.sort_by { |arel_attr,_| arel_attr.name } - binds = substitutes.map do |arel_attr, value| - [@klass.columns_hash[arel_attr.name], value] - end - - substitutes.each_with_index do |tuple, i| - tuple[1] = conn.substitute_at(binds[i][0], i) - end + substitutes, binds = substitute_values values if values.empty? # empty insert im.values = Arel.sql(connection.empty_insert_statement_value) @@ -73,7 +62,7 @@ module ActiveRecord im.insert substitutes end - conn.insert( + @klass.connection.insert( im, 'SQL', primary_key, @@ -82,6 +71,40 @@ module ActiveRecord binds) end + def _update_record(values, id, id_was) # :nodoc: + substitutes, binds = substitute_values values + + scope = @klass.unscoped + + if @klass.finder_needs_type_condition? + scope.unscope!(where: @klass.inheritance_column) + end + + relation = scope.where(@klass.primary_key => (id_was || id)) + bvs = binds + relation.bind_values + um = relation + .arel + .compile_update(substitutes, @klass.primary_key) + + @klass.connection.update( + um, + 'SQL', + bvs, + ) + end + + def substitute_values(values) # :nodoc: + binds = values.map do |arel_attr, value| + [@klass.columns_hash[arel_attr.name], value] + end + + substitutes = values.each_with_index.map do |(arel_attr, _), i| + [arel_attr, @klass.connection.substitute_at(binds[i][0])] + end + + [substitutes, binds] + end + # Initializes new record from relation while maintaining the current # scope. # @@ -141,34 +164,58 @@ module ActiveRecord first || new(attributes, &block) end - # Finds the first record with the given attributes, or creates a record with the attributes - # if one is not found. + # Finds the first record with the given attributes, or creates a record + # with the attributes if one is not found: # - # ==== Examples - # # Find the first user named Penélope or create a new one. + # # Find the first user named "Penélope" or create a new one. # User.find_or_create_by(first_name: 'Penélope') - # # => <User id: 1, first_name: 'Penélope', last_name: nil> + # # => #<User id: 1, first_name: "Penélope", last_name: nil> # - # # Find the first user named Penélope or create a new one. + # # Find the first user named "Penélope" or create a new one. # # We already have one so the existing record will be returned. # User.find_or_create_by(first_name: 'Penélope') - # # => <User id: 1, first_name: 'Penélope', last_name: nil> + # # => #<User id: 1, first_name: "Penélope", last_name: nil> # - # # Find the first user named Scarlett or create a new one with a particular last name. + # # Find the first user named "Scarlett" or create a new one with + # # a particular last name. # User.create_with(last_name: 'Johansson').find_or_create_by(first_name: 'Scarlett') - # # => <User id: 2, first_name: 'Scarlett', last_name: 'Johansson'> + # # => #<User id: 2, first_name: "Scarlett", last_name: "Johansson"> # - # # Find the first user named Scarlett or create a new one with a different last name. - # # We already have one so the existing record will be returned. + # This method accepts a block, which is passed down to +create+. The last example + # above can be alternatively written this way: + # + # # Find the first user named "Scarlett" or create a new one with a + # # different last name. # User.find_or_create_by(first_name: 'Scarlett') do |user| - # user.last_name = "O'Hara" + # user.last_name = 'Johansson' # end - # # => <User id: 2, first_name: 'Scarlett', last_name: 'Johansson'> + # # => #<User id: 2, first_name: "Scarlett", last_name: "Johansson"> + # + # This method always returns a record, but if creation was attempted and + # failed due to validation errors it won't be persisted, you get what + # +create+ returns in such situation. + # + # Please note *this method is not atomic*, it runs first a SELECT, and if + # there are no results an INSERT is attempted. If there are other threads + # or processes there is a race condition between both calls and it could + # be the case that you end up with two similar records. + # + # Whether that is a problem or not depends on the logic of the + # application, but in the particular case in which rows have a UNIQUE + # constraint an exception may be raised, just retry: + # + # begin + # CreditAccount.find_or_create_by(user_id: user.id) + # rescue ActiveRecord::RecordNotUnique + # retry + # end + # def find_or_create_by(attributes, &block) find_by(attributes) || create(attributes, &block) end - # Like <tt>find_or_create_by</tt>, but calls <tt>create!</tt> so an exception is raised if the created record is invalid. + # Like <tt>find_or_create_by</tt>, but calls <tt>create!</tt> so an exception + # is raised if the created record is invalid. def find_or_create_by!(attributes, &block) find_by(attributes) || create!(attributes, &block) end @@ -188,8 +235,8 @@ module ActiveRecord # Please see further details in the # {Active Record Query Interface guide}[http://guides.rubyonrails.org/active_record_querying.html#running-explain]. def explain - _, queries = collecting_queries_for_explain { exec_queries } - exec_explain(queries) + #TODO: Fix for binds. + exec_explain(collecting_queries_for_explain { exec_queries }) end # Converts relation objects to Array. @@ -198,21 +245,30 @@ module ActiveRecord @records end + # Serializes the relation objects Array. + def encode_with(coder) + coder.represent_seq(nil, to_a) + end + def as_json(options = nil) #:nodoc: to_a.as_json(options) end # Returns size of the records. def size - loaded? ? @records.length : count + loaded? ? @records.length : count(:all) end # Returns true if there are no records. def empty? return @records.empty? if loaded? - c = count - c.respond_to?(:zero?) ? c.zero? : c.empty? + if limit_value == 0 + true + else + c = count(:all) + c.respond_to?(:zero?) ? c.zero? : c.empty? + end end # Returns true if there are any records. @@ -236,8 +292,9 @@ module ActiveRecord # Scope all queries to the current scope. # # Comment.where(post_id: 1).scoping do - # Comment.first # SELECT * FROM comments WHERE post_id = 1 + # Comment.first # end + # # => SELECT "comments".* FROM "comments" WHERE "comments"."post_id" = 1 ORDER BY "comments"."id" ASC LIMIT 1 # # Please check unscoped if you want to remove all previous scopes (including # the default_scope) during the execution of a block. @@ -248,10 +305,11 @@ module ActiveRecord klass.current_scope = previous end - # Updates all records with details given if they match a set of conditions supplied, limits and order can - # also be supplied. This method constructs a single SQL UPDATE statement and sends it straight to the - # database. It does not instantiate the involved models and it does not trigger Active Record callbacks - # or validations. + # Updates all records in the current relation with details given. This method constructs a single SQL UPDATE + # statement and sends it straight to the database. It does not instantiate the involved models and it does not + # trigger Active Record callbacks or validations. Values passed to `update_all` will not go through + # ActiveRecord's type-casting behavior. It should receive only values that can be passed as-is to the SQL + # database. # # ==== Parameters # @@ -270,7 +328,7 @@ module ActiveRecord def update_all(updates) raise ArgumentError, "Empty list of attributes to change" if updates.blank? - stmt = Arel::UpdateManager.new(arel.engine) + stmt = Arel::UpdateManager.new stmt.set Arel.sql(@klass.send(:sanitize_sql_for_assignment, updates)) stmt.table(table) @@ -284,7 +342,8 @@ module ActiveRecord stmt.wheres = arel.constraints end - @klass.connection.update stmt, 'SQL', bind_values + bvs = arel.bind_values + bind_values + @klass.connection.update stmt, 'SQL', bvs end # Updates an object (or multiple objects) and saves it to the database, if validations pass. @@ -308,7 +367,7 @@ module ActiveRecord id.map.with_index { |one_id, idx| update(one_id, attributes[idx]) } else object = find(id) - object.update_attributes(attributes) + object.update(attributes) object end end @@ -342,7 +401,7 @@ module ActiveRecord if conditions where(conditions).destroy_all else - to_a.each {|object| object.destroy }.tap { reset } + to_a.each(&:destroy).tap { reset } end end @@ -388,17 +447,26 @@ module ActiveRecord # If you need to destroy dependent associations or call your <tt>before_*</tt> or # +after_destroy+ callbacks, use the +destroy_all+ method instead. # - # If a limit scope is supplied, +delete_all+ raises an ActiveRecord error: + # If an invalid method is supplied, +delete_all+ raises an ActiveRecord error: # # Post.limit(100).delete_all - # # => ActiveRecord::ActiveRecordError: delete_all doesn't support limit scope + # # => ActiveRecord::ActiveRecordError: delete_all doesn't support limit def delete_all(conditions = nil) - raise ActiveRecordError.new("delete_all doesn't support limit scope") if self.limit_value + invalid_methods = INVALID_METHODS_FOR_DELETE_ALL.select { |method| + if MULTI_VALUE_METHODS.include?(method) + send("#{method}_values").any? + else + send("#{method}_value") + end + } + if invalid_methods.any? + raise ActiveRecordError.new("delete_all doesn't support #{invalid_methods.join(', ')}") + end if conditions where(conditions).delete_all else - stmt = Arel::DeleteManager.new(arel.engine) + stmt = Arel::DeleteManager.new stmt.from(table) if joins_values.any? @@ -444,17 +512,7 @@ module ActiveRecord # # Post.where(published: true).load # => #<ActiveRecord::Relation> def load - unless loaded? - # We monitor here the entire execution rather than individual SELECTs - # because from the point of view of the user fetching the records of a - # relation is a single unit of work. You want to know if this call takes - # too long, not if the individual queries take too long. - # - # It could be the case that none of the queries involved surpass the - # threshold, and at the same time the sum of them all does. The user - # should get a query plan logged in that case. - logging_query_plan { exec_queries } - end + exec_queries unless loaded? self end @@ -466,34 +524,55 @@ module ActiveRecord end def reset - @first = @last = @to_sql = @order_clause = @scope_for_create = @arel = @loaded = nil + @last = @to_sql = @order_clause = @scope_for_create = @arel = @loaded = nil @should_eager_load = @join_dependency = nil @records = [] + @offsets = {} self end # Returns sql statement for the relation. # - # Users.where(name: 'Oscar').to_sql + # User.where(name: 'Oscar').to_sql # # => SELECT "users".* FROM "users" WHERE "users"."name" = 'Oscar' def to_sql - @to_sql ||= klass.connection.to_sql(arel, bind_values.dup) - end - - # Returns a hash of where conditions - # - # Users.where(name: 'Oscar').where_values_hash - # # => {name: "oscar"} - def where_values_hash - equalities = with_default_scope.where_values.grep(Arel::Nodes::Equality).find_all { |node| - node.left.relation.name == table_name + @to_sql ||= begin + relation = self + connection = klass.connection + visitor = connection.visitor + + if eager_loading? + find_with_associations { |rel| relation = rel } + end + + arel = relation.arel + binds = (arel.bind_values + relation.bind_values).dup + binds.map! { |bv| connection.quote(*bv.reverse) } + collect = visitor.accept(arel.ast, Arel::Collectors::Bind.new) + collect.substitute_binds(binds).join + end + end + + # Returns a hash of where conditions. + # + # User.where(name: 'Oscar').where_values_hash + # # => {name: "Oscar"} + def where_values_hash(relation_table_name = table_name) + equalities = where_values.grep(Arel::Nodes::Equality).find_all { |node| + node.left.relation.name == relation_table_name } binds = Hash[bind_values.find_all(&:first).map { |column, v| [column.name, v] }] Hash[equalities.map { |where| name = where.left.name - [name, binds.fetch(name.to_s) { where.right }] + [name, binds.fetch(name.to_s) { + case where.right + when Array then where.right.map(&:val) + else + where.right.val + end + }] }] end @@ -516,9 +595,17 @@ module ActiveRecord includes_values & joins_values end + # +uniq+ and +uniq!+ are silently deprecated. +uniq_value+ delegates to +distinct_value+ + # to maintain backwards compatibility. Use +distinct_value+ instead. + def uniq_value + distinct_value + end + # Compares two relations for equality. def ==(other) case other + when Associations::CollectionProxy, AssociationRelation + self == other.to_a when Relation other.to_sql == to_sql when Array @@ -530,16 +617,6 @@ module ActiveRecord q.pp(self.to_a) end - def with_default_scope #:nodoc: - if default_scoped? && default_scope = klass.send(:build_default_scope) - default_scope = default_scope.merge(self) - default_scope.default_scoped = false - default_scope - else - self - end - end - # Returns true if relation is blank. def blank? to_a.blank? @@ -556,32 +633,32 @@ module ActiveRecord "#<#{self.class.name} [#{entries.join(', ')}]>" end - private + protected - def exec_queries - default_scoped = with_default_scope + attr_reader :predicate_builder - if default_scoped.equal?(self) - @records = eager_loading? ? find_with_associations : @klass.find_by_sql(arel, bind_values) + private - preload = preload_values - preload += includes_values unless eager_loading? - preload.each do |associations| - ActiveRecord::Associations::Preloader.new(@records, associations).run - end + def exec_queries + @records = eager_loading? ? find_with_associations : @klass.find_by_sql(arel, arel.bind_values + bind_values) - # @readonly_value is true only if set explicitly. @implicit_readonly is true if there - # are JOINS and no explicit SELECT. - readonly = readonly_value.nil? ? @implicit_readonly : readonly_value - @records.each { |record| record.readonly! } if readonly - else - @records = default_scoped.to_a + preload = preload_values + preload += includes_values unless eager_loading? + preloader = build_preloader + preload.each do |associations| + preloader.preload @records, associations end + @records.each(&:readonly!) if readonly_value + @loaded = true @records end + def build_preloader + ActiveRecord::Associations::Preloader.new + end + def references_eager_loaded_tables? joined_tables = arel.join_sources.map do |join| if join.is_a?(Arel::Nodes::StringJoin) @@ -594,38 +671,16 @@ module ActiveRecord joined_tables += [table.name, table.table_alias] # always convert table names to downcase as in Oracle quoted table names are in uppercase - joined_tables = joined_tables.flatten.compact.map { |t| t.downcase }.uniq - string_tables = tables_in_string(to_sql) + joined_tables = joined_tables.flatten.compact.map(&:downcase).uniq - if (references_values - joined_tables).any? - true - elsif (string_tables - joined_tables).any? - ActiveSupport::Deprecation.warn( - "It looks like you are eager loading table(s) (one of: #{string_tables.join(', ')}) " \ - "that are referenced in a string SQL snippet. For example: \n" \ - "\n" \ - " Post.includes(:comments).where(\"comments.title = 'foo'\")\n" \ - "\n" \ - "Currently, Active Record recognises the table in the string, and knows to JOIN the " \ - "comments table to the query, rather than loading comments in a separate query. " \ - "However, doing this without writing a full-blown SQL parser is inherently flawed. " \ - "Since we don't want to write an SQL parser, we are removing this functionality. " \ - "From now on, you must explicitly tell Active Record when you are referencing a table " \ - "from a string:\n" \ - "\n" \ - " Post.includes(:comments).where(\"comments.title = 'foo'\").references(:comments)\n\n" - ) - true - else - false - end + (references_values - joined_tables).any? end def tables_in_string(string) return [] if string.blank? # always convert table names to downcase as in Oracle quoted table names are in uppercase # ignore raw_sql_ that is used by Oracle adapter as alias for limit/offset subqueries - string.scan(/([a-zA-Z_][.\w]+).?\./).flatten.map{ |s| s.downcase }.uniq - ['raw_sql_'] + string.scan(/([a-zA-Z_][.\w]+).?\./).flatten.map(&:downcase).uniq - ['raw_sql_'] end end end |