diff options
Diffstat (limited to 'activerecord/lib/active_record')
4 files changed, 56 insertions, 5 deletions
diff --git a/activerecord/lib/active_record/associations/join_dependency.rb b/activerecord/lib/active_record/associations/join_dependency.rb index 0e98a3b3a4..9f183c3e7e 100644 --- a/activerecord/lib/active_record/associations/join_dependency.rb +++ b/activerecord/lib/active_record/associations/join_dependency.rb @@ -103,9 +103,14 @@ module ActiveRecord join_root.drop(1).map!(&:reflection) end - def join_constraints(outer_joins) + def join_constraints(outer_joins, join_type) joins = join_root.children.flat_map { |child| - make_inner_joins join_root, child + + if join_type == Arel::Nodes::OuterJoin + make_left_outer_joins join_root, child + else + make_inner_joins join_root, child + end } joins.concat outer_joins.flat_map { |oj| @@ -176,6 +181,14 @@ module ActiveRecord [info] + child.children.flat_map { |c| make_outer_joins(child, c) } end + def make_left_outer_joins(parent, child) + tables = child.tables + join_type = Arel::Nodes::OuterJoin + info = make_constraints parent, child, tables, join_type + + [info] + child.children.flat_map { |c| make_left_outer_joins(child, c) } + end + def make_inner_joins(parent, child) tables = child.tables join_type = Arel::Nodes::InnerJoin diff --git a/activerecord/lib/active_record/querying.rb b/activerecord/lib/active_record/querying.rb index 87a1988f2f..7ab2108de0 100644 --- a/activerecord/lib/active_record/querying.rb +++ b/activerecord/lib/active_record/querying.rb @@ -7,7 +7,7 @@ module ActiveRecord delegate :find_by, :find_by!, to: :all delegate :destroy, :destroy_all, :delete, :delete_all, :update, :update_all, to: :all delegate :find_each, :find_in_batches, :in_batches, to: :all - delegate :select, :group, :order, :except, :reorder, :limit, :offset, :joins, :or, + delegate :select, :group, :order, :except, :reorder, :limit, :offset, :joins, :left_outer_joins, :or, :where, :rewhere, :preload, :eager_load, :includes, :from, :lock, :readonly, :having, :create_with, :uniq, :distinct, :references, :none, :unscope, to: :all delegate :count, :average, :minimum, :maximum, :sum, :calculate, to: :all diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb index 392b462aa9..ad7ea199d6 100644 --- a/activerecord/lib/active_record/relation.rb +++ b/activerecord/lib/active_record/relation.rb @@ -4,7 +4,7 @@ module ActiveRecord # = Active Record \Relation class Relation MULTI_VALUE_METHODS = [:includes, :eager_load, :preload, :select, :group, - :order, :joins, :references, + :order, :joins, :left_outer_joins, :references, :extending, :unscope] SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :reordering, diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb index ad6c7fa2e5..27e7948b10 100644 --- a/activerecord/lib/active_record/relation/query_methods.rb +++ b/activerecord/lib/active_record/relation/query_methods.rb @@ -428,6 +428,25 @@ module ActiveRecord self end + # Performs a left outer joins on +args+: + # + # User.left_outer_joins(:posts) + # => SELECT "users".* FROM "users" LEFT OUTER JOIN "posts" ON "posts"."user_id" = "users"."id" + # + def left_outer_joins(*args) + check_if_method_has_arguments!(:left_outer_joins, args) + + args.compact! + args.flatten! + + spawn.left_outer_joins!(*args) + end + + def left_outer_joins!(*args) # :nodoc: + self.left_outer_joins_values += args + self + end + # Returns a new relation, which is the result of filtering the current relation # according to the conditions in the arguments. # @@ -878,6 +897,7 @@ module ActiveRecord arel = Arel::SelectManager.new(table) build_joins(arel, joins_values.flatten) unless joins_values.empty? + build_left_outer_joins(arel, left_outer_joins_values.flatten) unless left_outer_joins_values.empty? arel.where(where_clause.ast) unless where_clause.empty? arel.having(having_clause.ast) unless having_clause.empty? @@ -937,6 +957,19 @@ module ActiveRecord end end + def build_left_outer_joins(manager, outer_joins) + buckets = outer_joins.group_by do |join| + case join + when Hash, Symbol, Array + :association_join + else + raise ArgumentError, 'only Hash, Symbol and Array are allowed' + end + end + + build_join_query(manager, buckets, Arel::Nodes::OuterJoin) + end + def build_joins(manager, joins) buckets = joins.group_by do |join| case join @@ -952,6 +985,11 @@ module ActiveRecord raise 'unknown class: %s' % join.class.name end end + + build_join_query(manager, buckets, Arel::Nodes::InnerJoin) + end + + def build_join_query(manager, buckets, join_type) buckets.default = [] association_joins = buckets[:association_join] @@ -967,7 +1005,7 @@ module ActiveRecord join_list ) - join_infos = join_dependency.join_constraints stashed_association_joins + join_infos = join_dependency.join_constraints stashed_association_joins, join_type join_infos.each do |info| info.joins.each { |join| manager.from(join) } |