feat: quiz and rbac

migrations/0058_quiz_multi_choice.up.sql

@@ -0,0 +1,14 @@
+-- Multiple-choice questions with more than one correct answer.
+--
+-- A question marked multi asks the reader to "select all that apply"; it is
+-- scored correct only when the chosen set equals the correct set exactly. A
+-- single-answer question keeps exactly one correct option.
+ALTER TABLE quiz_questions ADD COLUMN IF NOT EXISTS multi BOOLEAN NOT NULL DEFAULT FALSE;
+
+-- An answer is now a set of options. Arrays can't carry a foreign key; that
+-- is safe here because a quiz's options are frozen once anyone has answered,
+-- and options only ever go away with their whole question.
+ALTER TABLE quiz_answers ADD COLUMN IF NOT EXISTS option_ids UUID[];
+UPDATE quiz_answers SET option_ids = ARRAY[option_id]
+WHERE option_id IS NOT NULL AND option_ids IS NULL;
+ALTER TABLE quiz_answers DROP COLUMN IF EXISTS option_id;