feat(db): add migration 0104 issue polymorphic project

1-- 0104_issue_polymorphic_project.sql

2-- Make issue collaboration dimensions (comment / reaction / watch / event_line

3-- / pin) polymorphic between issue and project. Each row must reference

4-- exactly one of (issue_id, comment_id for reactions, project_id).

5--

6-- Documentation only; not run by the migration runner per project policy.

8-- ---------------------------------------------------------------------------

9-- comment : (issue_id XOR project_id)

10-- ---------------------------------------------------------------------------

11ALTER TABLE comment

12 ALTER COLUMN issue_id DROP NOT NULL,

13 ADD COLUMN IF NOT EXISTS project_id uuid REFERENCES project(id) ON DELETE CASCADE,

14 ADD CONSTRAINT comment_target_xor

15 CHECK ((issue_id IS NOT NULL) <> (project_id IS NOT NULL));

16CREATE INDEX IF NOT EXISTS idx_comment_project ON comment (project_id);

18-- ---------------------------------------------------------------------------

19-- issue_reaction : exactly one of (issue_id, comment_id, project_id)

20-- ---------------------------------------------------------------------------

21ALTER TABLE issue_reaction

22 ADD COLUMN IF NOT EXISTS project_id uuid REFERENCES project(id) ON DELETE CASCADE,

23 ADD CONSTRAINT issue_reaction_target_exactly_one

24 CHECK (

25 ((issue_id IS NOT NULL)::int +

26 (comment_id IS NOT NULL)::int +

27 (project_id IS NOT NULL)::int) = 1

28 );

29CREATE INDEX IF NOT EXISTS idx_issue_reaction_project ON issue_reaction (project_id);

31-- ---------------------------------------------------------------------------

32-- issue_watch : (issue_id XOR project_id)

33-- ---------------------------------------------------------------------------

34ALTER TABLE issue_watch

35 ALTER COLUMN issue_id DROP NOT NULL,

36 ADD COLUMN IF NOT EXISTS project_id uuid REFERENCES project(id) ON DELETE CASCADE,

37 ADD CONSTRAINT issue_watch_target_xor

38 CHECK ((issue_id IS NOT NULL) <> (project_id IS NOT NULL));

39CREATE INDEX IF NOT EXISTS idx_issue_watch_project ON issue_watch (project_id);

41-- Rebuild unique indexes with partial filter so nullable columns are handled:

42DROP INDEX IF EXISTS idx_issue_watch_issue_user;

43CREATE UNIQUE INDEX IF NOT EXISTS idx_issue_watch_issue_user

44 ON issue_watch (issue_id, user_id) WHERE issue_id IS NOT NULL;

45CREATE UNIQUE INDEX IF NOT EXISTS idx_issue_watch_project_user

46 ON issue_watch (project_id, user_id) WHERE project_id IS NOT NULL;

48-- ---------------------------------------------------------------------------

49-- issue_event_line : (issue_id XOR project_id)

50-- ---------------------------------------------------------------------------

51ALTER TABLE issue_event_line

52 ALTER COLUMN issue_id DROP NOT NULL,

53 ADD COLUMN IF NOT EXISTS project_id uuid REFERENCES project(id) ON DELETE CASCADE,

54 ADD CONSTRAINT issue_event_target_xor

55 CHECK ((issue_id IS NOT NULL) <> (project_id IS NOT NULL));

56CREATE INDEX IF NOT EXISTS idx_issue_event_project ON issue_event_line (project_id);

58-- ---------------------------------------------------------------------------

59-- issue_pin : (issue_id XOR project_id)

60-- ---------------------------------------------------------------------------

61ALTER TABLE issue_pin

62 ALTER COLUMN issue_id DROP NOT NULL,

63 ADD COLUMN IF NOT EXISTS project_id uuid REFERENCES project(id) ON DELETE CASCADE,

64 ADD CONSTRAINT issue_pin_target_xor

65 CHECK ((issue_id IS NOT NULL) <> (project_id IS NOT NULL));

66CREATE INDEX IF NOT EXISTS idx_issue_pin_project ON issue_pin (project_id);