Update constraint on resource_state_events table

db/migrate/20200519074709_update_resource_state_events_constraint_to_support_epic_id.rb

+# frozen_string_literal: true
+
+class UpdateResourceStateEventsConstraintToSupportEpicId < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  OLD_CONSTRAINT = 'resource_state_events_must_belong_to_issue_or_merge_request'
+  CONSTRAINT_NAME = 'resource_state_events_must_belong_to_issue_or_merge_request_or_epic'
+
+  def up
+    remove_check_constraint :resource_state_events, OLD_CONSTRAINT
+    add_check_constraint :resource_state_events, "(issue_id != NULL AND merge_request_id IS NULL AND epic_id IS NULL) OR " \
+      "(issue_id IS NULL AND merge_request_id != NULL AND epic_id IS NULL) OR" \
+      "(issue_id IS NULL AND merge_request_id IS NULL AND epic_id != NULL)", CONSTRAINT_NAME
+  end
+
+  def down
+    remove_check_constraint :resource_state_events, CONSTRAINT_NAME
+    add_check_constraint :resource_state_events, '(issue_id != NULL AND merge_request_id IS NULL) OR (merge_request_id != NULL AND issue_id IS NULL)', OLD_CONSTRAINT
+  end
+end

db/structure.sql

@@ -5895,7 +5895,7 @@ CREATE TABLE public.resource_state_events (
     created_at timestamp with time zone NOT NULL,
     state smallint NOT NULL,
     epic_id integer,
-    CONSTRAINT resource_state_events_must_belong_to_issue_or_merge_request CHECK ((((issue_id <> NULL::bigint) AND (merge_request_id IS NULL)) OR ((merge_request_id <> NULL::bigint) AND (issue_id IS NULL))))
+    CONSTRAINT resource_state_events_must_belong_to_issue_or_merge_request_or_ CHECK ((((issue_id <> NULL::bigint) AND (merge_request_id IS NULL) AND (epic_id IS NULL)) OR ((issue_id IS NULL) AND (merge_request_id <> NULL::bigint) AND (epic_id IS NULL)) OR ((issue_id IS NULL) AND (merge_request_id IS NULL) AND (epic_id <> NULL::integer))))
 );
 
 CREATE SEQUENCE public.resource_state_events_id_seq
@@ -14026,6 +14026,7 @@ COPY "schema_migrations" (version) FROM STDIN;
 20200515155620
 20200518091745
 20200518133123
+20200519074709
 20200519101002
 20200519115908
 20200519171058