Add latest changes from gitlab-org/gitlab@13-4-stable-ee

1 files changed, 37 insertions, 0 deletions

diff --git a/app/models/concerns/from_intersect.rb b/app/models/concerns/from_intersect.rb
new file mode 100644
index 00000000000..428e63eb45e
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+++ b/app/models/concerns/from_intersect.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module FromIntersect
+  extend ActiveSupport::Concern
+
+  class_methods do
+    # Produces a query that uses a FROM to select data using an INTERSECT.
+    #
+    # Example:
+    #     groups = Group.from_intersect([group1.self_and_hierarchy, group2.self_and_hierarchy])
+    #
+    # This would produce the following SQL query:
+    #
+    #     SELECT *
+    #     FROM (
+    #       SELECT "namespaces". *
+    #       ...
+    #
+    #       INTERSECT
+    #
+    #       SELECT "namespaces". *
+    #       ...
+    #     ) groups;
+    #
+    # members - An Array of ActiveRecord::Relation objects to use in the intersect.
+    #
+    # remove_duplicates - A boolean indicating if duplicate entries should be
+    #                     removed. Defaults to true.
+    #
+    # alias_as - The alias to use for the sub query. Defaults to the name of the
+    #            table of the current model.
+    # rubocop: disable Gitlab/Intersect
+    extend FromSetOperator
+    define_set_operator Gitlab::SQL::Intersect
+    # rubocop: enable Gitlab/Intersect
+  end
+end