diff options
Diffstat (limited to 'activerecord/lib/active_record/relation.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation.rb | 170 |
1 files changed, 76 insertions, 94 deletions
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb index 913f6f88f2..4e86e905ed 100644 --- a/activerecord/lib/active_record/relation.rb +++ b/activerecord/lib/active_record/relation.rb @@ -17,18 +17,14 @@ module ActiveRecord include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation attr_reader :table, :klass, :loaded - attr_accessor :default_scoped, :proxy_association 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 + @loaded = false end def initialize_copy(other) @@ -76,10 +72,10 @@ module ActiveRecord def update_record(values, id, id_was) # :nodoc: substitutes, binds = substitute_values values um = @klass.unscoped.where(@klass.arel_table[@klass.primary_key].eq(id_was || id)).arel.compile_update(substitutes) - + @klass.connection.update( - um, - 'SQL', + um, + 'SQL', binds) end @@ -94,7 +90,7 @@ module ActiveRecord end [substitutes, binds] - end + end # Initializes new record from relation while maintaining the current # scope. @@ -155,34 +151,58 @@ 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 @@ -224,7 +244,7 @@ module ActiveRecord def empty? return @records.empty? if loaded? - c = count + c = count(:all) c.respond_to?(:zero?) ? c.zero? : c.empty? end @@ -290,7 +310,7 @@ module ActiveRecord stmt.table(table) stmt.key = table[primary_key] - if with_default_scope.joins_values.any? + if joins_values.any? @klass.connection.join_to_update(stmt, arel) else stmt.take(arel.limit) @@ -415,7 +435,7 @@ module ActiveRecord stmt = Arel::DeleteManager.new(arel.engine) stmt.from(table) - if with_default_scope.joins_values.any? + if joins_values.any? @klass.connection.join_to_delete(stmt, arel, table[primary_key]) else stmt.wheres = arel.constraints @@ -481,7 +501,22 @@ module ActiveRecord # 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) + @to_sql ||= begin + relation = self + connection = klass.connection + visitor = connection.visitor + + if eager_loading? + join_dependency = construct_join_dependency + relation = construct_relation_for_association_find(join_dependency) + end + + ast = relation.arel.ast + binds = relation.bind_values.dup + visitor.accept(ast) do + connection.quote(*binds.shift.reverse) + end + end end # Returns a hash of where conditions. @@ -489,11 +524,12 @@ module ActiveRecord # User.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| + equalities = where_values.grep(Arel::Nodes::Equality).find_all { |node| node.left.relation.name == table_name } binds = Hash[bind_values.find_all(&:first).map { |column, v| [column.name, v] }] + binds.merge!(Hash[bind_values.find_all(&:first).map { |column, v| [column.name, v] }]) Hash[equalities.map { |where| name = where.left.name @@ -540,16 +576,6 @@ 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? @@ -569,34 +595,23 @@ module ActiveRecord private def exec_queries - default_scoped = with_default_scope - - if default_scoped.equal?(self) - @records = eager_loading? ? find_with_associations : @klass.find_by_sql(arel, bind_values) + @records = eager_loading? ? find_with_associations : @klass.find_by_sql(arel, bind_values) - preload = preload_values - preload += includes_values unless eager_loading? - preload.each do |associations| - ActiveRecord::Associations::Preloader.new(@records, associations).run - end - - # @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? + preload.each do |associations| + ActiveRecord::Associations::Preloader.new(@records, associations).run end + @records.each { |record| record.readonly! } if readonly_value + @loaded = true @records end def references_eager_loaded_tables? joined_tables = arel.join_sources.map do |join| - if join.is_a?(Arel::Nodes::StringJoin) - tables_in_string(join.left) - else + unless join.is_a?(Arel::Nodes::StringJoin) [join.left.table_name, join.left.table_alias] end end @@ -605,41 +620,8 @@ module ActiveRecord # 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) - - if (references_values - joined_tables).any? - true - elsif !ActiveRecord::Base.disable_implicit_join_references && - (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 recognizes 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" \ - "If you don't rely on implicit join references you can disable the feature entirely " \ - "by setting `config.active_record.disable_implicit_join_references = true`." - ) - true - else - false - end - 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_'] + (references_values - joined_tables).any? end end end |