diff options
Diffstat (limited to 'activerecord/lib/active_record/relation.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation.rb | 273 |
1 files changed, 167 insertions, 106 deletions
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb index ad54d84665..392b462aa9 100644 --- a/activerecord/lib/active_record/relation.rb +++ b/activerecord/lib/active_record/relation.rb @@ -1,40 +1,39 @@ -# -*- coding: utf-8 -*- -require 'arel/collectors/bind' +require "arel/collectors/bind" module ActiveRecord - # = Active Record Relation + # = 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, + :order, :joins, :references, :extending, :unscope] - SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :from, :reordering, - :reverse_order, :distinct, :create_with, :uniq] + SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :reordering, + :reverse_order, :distinct, :create_with] + CLAUSE_METHODS = [:where, :having, :from] INVALID_METHODS_FOR_DELETE_ALL = [:limit, :distinct, :offset, :group, :having] - VALUE_METHODS = MULTI_VALUE_METHODS + SINGLE_VALUE_METHODS + VALUE_METHODS = MULTI_VALUE_METHODS + SINGLE_VALUE_METHODS + CLAUSE_METHODS + include Enumerable include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation - attr_reader :table, :klass, :loaded + attr_reader :table, :klass, :loaded, :predicate_builder alias :model :klass alias :loaded? :loaded - def initialize(klass, table, values = {}) + def initialize(klass, table, predicate_builder, values = {}) @klass = klass @table = table @values = values @offsets = {} @loaded = false + @predicate_builder = predicate_builder end def initialize_copy(other) # This method is a hot spot, so for now, use Hash[] to dup the hash. # https://bugs.ruby-lang.org/issues/7166 @values = Hash[@values] - @values[:bind] = @values[:bind].dup if @values.key? :bind reset end @@ -81,22 +80,26 @@ module ActiveRecord scope.unscope!(where: @klass.inheritance_column) end - um = scope.where(@klass.arel_table[@klass.primary_key].eq(id_was || id)).arel.compile_update(substitutes, @klass.primary_key) + relation = scope.where(@klass.primary_key => (id_was || id)) + bvs = binds + relation.bound_attributes + um = relation + .arel + .compile_update(substitutes, @klass.primary_key) @klass.connection.update( um, 'SQL', - binds) + bvs, + ) end def substitute_values(values) # :nodoc: - substitutes = values.sort_by { |arel_attr,_| arel_attr.name } - binds = substitutes.map do |arel_attr, value| - [@klass.columns_hash[arel_attr.name], value] + binds = values.map do |arel_attr, value| + QueryAttribute.new(arel_attr.name, value, klass.type_for_attribute(arel_attr.name)) end - substitutes.each_with_index do |tuple, i| - tuple[1] = @klass.connection.substitute_at(binds[i][0], i) + substitutes = values.map do |(arel_attr, _)| + [arel_attr, connection.substitute_at(klass.columns_hash[arel_attr.name])] end [substitutes, binds] @@ -105,7 +108,7 @@ module ActiveRecord # Initializes new record from relation while maintaining the current # scope. # - # Expects arguments in the same format as +Base.new+. + # Expects arguments in the same format as {ActiveRecord::Base.new}[rdoc-ref:Core.new]. # # users = User.where(name: 'DHH') # user = users.new # => #<User id: nil, name: "DHH", created_at: nil, updated_at: nil> @@ -123,28 +126,32 @@ module ActiveRecord # Tries to create a new record with the same scoped attributes # defined in the relation. Returns the initialized object if validation fails. # - # Expects arguments in the same format as +Base.create+. + # Expects arguments in the same format as + # {ActiveRecord::Base.create}[rdoc-ref:Persistence::ClassMethods#create]. # # ==== Examples + # # users = User.where(name: 'Oscar') - # users.create # #<User id: 3, name: "oscar", ...> + # users.create # => #<User id: 3, name: "oscar", ...> # # users.create(name: 'fxn') - # users.create # #<User id: 4, name: "fxn", ...> + # users.create # => #<User id: 4, name: "fxn", ...> # # users.create { |user| user.name = 'tenderlove' } - # # #<User id: 5, name: "tenderlove", ...> + # # => #<User id: 5, name: "tenderlove", ...> # # users.create(name: nil) # validation on name - # # #<User id: nil, name: nil, ...> + # # => #<User id: nil, name: nil, ...> def create(*args, &block) scoping { @klass.create(*args, &block) } end - # Similar to #create, but calls +create!+ on the base class. Raises - # an exception if a validation error occurs. + # Similar to #create, but calls + # {create!}[rdoc-ref:Persistence::ClassMethods#create!] + # on the base class. Raises an exception if a validation error occurs. # - # Expects arguments in the same format as <tt>Base.create!</tt>. + # Expects arguments in the same format as + # {ActiveRecord::Base.create!}[rdoc-ref:Persistence::ClassMethods#create!]. def create!(*args, &block) scoping { @klass.create!(*args, &block) } end @@ -178,7 +185,7 @@ module ActiveRecord # User.create_with(last_name: 'Johansson').find_or_create_by(first_name: 'Scarlett') # # => #<User id: 2, first_name: "Scarlett", last_name: "Johansson"> # - # This method accepts a block, which is passed down to +create+. The last example + # 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 @@ -190,7 +197,7 @@ module ActiveRecord # # 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. + # #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 @@ -202,7 +209,9 @@ module ActiveRecord # constraint an exception may be raised, just retry: # # begin - # CreditAccount.find_or_create_by(user_id: user.id) + # CreditAccount.transaction(requires_new: true) do + # CreditAccount.find_or_create_by(user_id: user.id) + # end # rescue ActiveRecord::RecordNotUnique # retry # end @@ -211,13 +220,15 @@ module ActiveRecord find_by(attributes) || create(attributes, &block) end - # Like <tt>find_or_create_by</tt>, but calls <tt>create!</tt> so an exception + # Like #find_or_create_by, but calls + # {create!}[rdoc-ref:Persistence::ClassMethods#create!] 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 - # Like <tt>find_or_create_by</tt>, but calls <tt>new</tt> instead of <tt>create</tt>. + # Like #find_or_create_by, but calls {new}[rdoc-ref:Core#new] + # instead of {create}[rdoc-ref:Persistence::ClassMethods#create]. def find_or_initialize_by(attributes, &block) find_by(attributes) || new(attributes, &block) end @@ -268,22 +279,54 @@ module ActiveRecord end end + # Returns true if there are no records. + def none? + return super if block_given? + empty? + end + # Returns true if there are any records. def any? - if block_given? - to_a.any? { |*block_args| yield(*block_args) } - else - !empty? - end + return super if block_given? + !empty? + end + + # Returns true if there is exactly one record. + def one? + return super if block_given? + limit_value ? to_a.one? : size == 1 end # Returns true if there is more than one record. def many? - if block_given? - to_a.many? { |*block_args| yield(*block_args) } - else - limit_value ? to_a.many? : size > 1 - end + return super if block_given? + limit_value ? to_a.many? : size > 1 + end + + # Returns a cache key that can be used to identify the records fetched by + # this query. The cache key is built with a fingerprint of the sql query, + # the number of records matched by the query and a timestamp of the last + # updated record. When a new record comes to match the query, or any of + # the existing records is updated or deleted, the cache key changes. + # + # Product.where("name like ?", "%Cosmic Encounter%").cache_key + # # => "products/query-1850ab3d302391b85b8693e941286659-1-20150714212553907087000" + # + # If the collection is loaded, the method will iterate through the records + # to generate the timestamp, otherwise it will trigger one SQL query like: + # + # SELECT COUNT(*), MAX("products"."updated_at") FROM "products" WHERE (name like '%Cosmic Encounter%') + # + # You can also pass a custom timestamp column to fetch the timestamp of the + # last updated record. + # + # Product.where("name like ?", "%Game%").cache_key(:last_reviewed_at) + # + # You can customize the strategy to generate the key on a per model basis + # overriding ActiveRecord::Base#collection_cache_key. + def cache_key(timestamp_column = :updated_at) + @cache_keys ||= {} + @cache_keys[timestamp_column] ||= @klass.collection_cache_key(self, timestamp_column) end # Scope all queries to the current scope. @@ -302,10 +345,11 @@ 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 + # Active Record's type-casting behavior. It should receive only values that can be passed as-is to the SQL + # database. # # ==== Parameters # @@ -324,7 +368,7 @@ 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) @@ -338,8 +382,7 @@ module ActiveRecord stmt.wheres = arel.constraints end - bvs = bind_values + arel.bind_values - @klass.connection.update stmt, 'SQL', bvs + @klass.connection.update stmt, 'SQL', bound_attributes end # Updates an object (or multiple objects) and saves it to the database, if validations pass. @@ -358,20 +401,39 @@ module ActiveRecord # # Updates multiple records # people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy" } } # Person.update(people.keys, people.values) - def update(id, attributes) + # + # # Updates multiple records from the result of a relation + # people = Person.where(group: 'expert') + # people.update(group: 'masters') + # + # Note: Updating a large number of records will run an + # UPDATE query for each record, which may cause a performance + # issue. So if it is not needed to run callbacks for each update, it is + # preferred to use #update_all for updating all records using + # a single query. + def update(id = :all, attributes) if id.is_a?(Array) id.map.with_index { |one_id, idx| update(one_id, attributes[idx]) } + elsif id == :all + to_a.each { |record| record.update(attributes) } else + if ActiveRecord::Base === id + id = id.id + ActiveSupport::Deprecation.warn(<<-MSG.squish) + You are passing an instance of ActiveRecord::Base to `update`. + Please pass the id of the object by calling `.id` + MSG + end object = find(id) object.update(attributes) object end end - # Destroys the records matching +conditions+ by instantiating each - # record and calling its +destroy+ method. Each object's callbacks are - # executed (including <tt>:dependent</tt> association options). Returns the - # collection of objects that were destroyed; each will be frozen, to + # Destroys the records by instantiating each + # record and calling its {#destroy}[rdoc-ref:Persistence#destroy] method. + # Each object's callbacks are executed (including <tt>:dependent</tt> association options). + # Returns the collection of objects that were destroyed; each will be frozen, to # reflect that no changes should be made (since they can't be persisted). # # Note: Instantiation, callback execution, and deletion of each @@ -379,31 +441,26 @@ module ActiveRecord # once. It generates at least one SQL +DELETE+ query per record (or # possibly more, to enforce your callbacks). If you want to delete many # rows quickly, without concern for their associations or callbacks, use - # +delete_all+ instead. - # - # ==== Parameters - # - # * +conditions+ - A string, array, or hash that specifies which records - # to destroy. If omitted, all records are destroyed. See the - # Conditions section in the introduction to ActiveRecord::Base for - # more information. + # #delete_all instead. # # ==== Examples # - # Person.destroy_all("last_login < '2004-04-04'") - # Person.destroy_all(status: "inactive") # Person.where(age: 0..18).destroy_all def destroy_all(conditions = nil) if conditions + ActiveSupport::Deprecation.warn(<<-MESSAGE.squish) + Passing conditions to destroy_all is deprecated and will be removed in Rails 5.1. + To achieve the same use where(conditions).destroy_all + MESSAGE where(conditions).destroy_all else - to_a.each {|object| object.destroy }.tap { reset } + to_a.each(&:destroy).tap { reset } end end # Destroy an object (or multiple objects) that has the given id. The object is instantiated first, # therefore all callbacks and filters are fired off before the object is deleted. This method is - # less efficient than ActiveRecord#delete but allows cleanup methods and other actions to be run. + # less efficient than #delete but allows cleanup methods and other actions to be run. # # This essentially finds the object (or multiple objects) with the given id, creates a new object # from the attributes, and then calls destroy on it. @@ -428,22 +485,21 @@ module ActiveRecord end end - # Deletes the records matching +conditions+ without instantiating the records - # first, and hence not calling the +destroy+ method nor invoking callbacks. This - # is a single SQL DELETE statement that goes straight to the database, much more - # efficient than +destroy_all+. Be careful with relations though, in particular + # Deletes the records without instantiating the records + # first, and hence not calling the {#destroy}[rdoc-ref:Persistence#destroy] + # method nor invoking callbacks. + # This is a single SQL DELETE statement that goes straight to the database, much more + # efficient than #destroy_all. Be careful with relations though, in particular # <tt>:dependent</tt> rules defined on associations are not honored. Returns the # number of rows affected. # - # Post.delete_all("person_id = 5 AND (category = 'Something' OR category = 'Else')") - # Post.delete_all(["person_id = ? AND (category = ? OR category = ?)", 5, 'Something', 'Else']) # Post.where(person_id: 5).where(category: ['Something', 'Else']).delete_all # # Both calls delete the affected posts all at once with a single DELETE statement. # If you need to destroy dependent associations or call your <tt>before_*</tt> or - # +after_destroy+ callbacks, use the +destroy_all+ method instead. + # +after_destroy+ callbacks, use the #destroy_all method instead. # - # If an invalid method is supplied, +delete_all+ raises an ActiveRecord error: + # If an invalid method is supplied, #delete_all raises an ActiveRecordError: # # Post.limit(100).delete_all # # => ActiveRecord::ActiveRecordError: delete_all doesn't support limit @@ -451,8 +507,10 @@ module ActiveRecord invalid_methods = INVALID_METHODS_FOR_DELETE_ALL.select { |method| if MULTI_VALUE_METHODS.include?(method) send("#{method}_values").any? - else + elsif SINGLE_VALUE_METHODS.include?(method) send("#{method}_value") + elsif CLAUSE_METHODS.include?(method) + send("#{method}_clause").any? end } if invalid_methods.any? @@ -460,9 +518,13 @@ module ActiveRecord end if conditions + ActiveSupport::Deprecation.warn(<<-MESSAGE.squish) + Passing conditions to delete_all is deprecated and will be removed in Rails 5.1. + To achieve the same use where(conditions).delete_all + MESSAGE where(conditions).delete_all else - stmt = Arel::DeleteManager.new(arel.engine) + stmt = Arel::DeleteManager.new stmt.from(table) if joins_values.any? @@ -471,7 +533,7 @@ module ActiveRecord stmt.wheres = arel.constraints end - affected = @klass.connection.delete(stmt, 'SQL', bind_values) + affected = @klass.connection.delete(stmt, 'SQL', bound_attributes) reset affected @@ -486,7 +548,7 @@ module ActiveRecord # You can delete multiple rows at once by passing an Array of <tt>id</tt>s. # # Note: Although it is often much faster than the alternative, - # <tt>#destroy</tt>, skipping callbacks might bypass business logic in + # #destroy, skipping callbacks might bypass business logic in # your application that ensures referential integrity or performs other # essential jobs. # @@ -541,10 +603,10 @@ module ActiveRecord 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) + binds = relation.bound_attributes + binds = connection.prepare_binds_for_database(binds) + binds.map! { |value| connection.quote(value) } + collect = visitor.accept(relation.arel.ast, Arel::Collectors::Bind.new) collect.substitute_binds(binds).join end end @@ -554,22 +616,7 @@ module ActiveRecord # 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) { - case where.right - when Array then where.right.map(&:val) - else - where.right.val - end - }] - }] + where_clause.to_h(relation_table_name) end def scope_for_create @@ -591,11 +638,14 @@ 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. + # {#uniq}[rdoc-ref:QueryMethods#uniq] and + # {#uniq!}[rdoc-ref:QueryMethods#uniq!] are silently deprecated. + # #uniq_value delegates to #distinct_value to maintain backwards compatibility. + # Use #distinct_value instead. def uniq_value distinct_value end + deprecate uniq_value: :distinct_value # Compares two relations for equality. def ==(other) @@ -629,24 +679,35 @@ module ActiveRecord "#<#{self.class.name} [#{entries.join(', ')}]>" end + protected + + def load_records(records) + @records = records + @loaded = true + end + private def exec_queries - @records = eager_loading? ? find_with_associations : @klass.find_by_sql(arel, arel.bind_values + bind_values) + @records = eager_loading? ? find_with_associations : @klass.find_by_sql(arel, bound_attributes) preload = preload_values preload += includes_values unless eager_loading? - preloader = ActiveRecord::Associations::Preloader.new + preloader = build_preloader preload.each do |associations| preloader.preload @records, associations end - @records.each { |record| record.readonly! } if readonly_value + @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) @@ -659,7 +720,7 @@ 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 + joined_tables = joined_tables.flatten.compact.map(&:downcase).uniq (references_values - joined_tables).any? end @@ -668,7 +729,7 @@ module ActiveRecord 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 |