add: ver()

Signed-off-by: Kenneth Obsequio <k80308392@gmail.com>

database/junction_revamp.sql

@@ -0,0 +1,79 @@
+-- ═══════════════════════════════════════════════════════════════════════════
+-- JUNCTION REVAMP — Units and Lessons run independently        (Jul. 7, 2026)
+--
+--   courses ⇄ course_units ⇄ units ⇄ unit_lessons ⇄ lessons
+--
+-- Run order matters: create → backfill → relax progress FKs → drop old columns.
+-- Postgres / CockroachDB compatible. Take a backup before running.
+-- ═══════════════════════════════════════════════════════════════════════════
+
+BEGIN;
+
+-- ── 1. Junction tables ───────────────────────────────────────────────────────
+
+CREATE TABLE course_units (
+  course_unit_id BIGINT       GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  course_id      BIGINT       NOT NULL REFERENCES courses (course_id) ON DELETE CASCADE,
+  unit_id        BIGINT       NOT NULL REFERENCES units   (unit_id)   ON DELETE CASCADE,
+  order_index    INTEGER      NOT NULL DEFAULT 0,
+  "createdBy"    BIGINT       NULL,
+  "updatedBy"    BIGINT       NULL,
+  "createdAt"    TIMESTAMPTZ  NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  "updatedAt"    TIMESTAMPTZ  NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  CONSTRAINT uq_course_units_course_unit UNIQUE (course_id, unit_id)
+);
+
+CREATE INDEX idx_course_units_course_id ON course_units (course_id);
+CREATE INDEX idx_course_units_unit_id   ON course_units (unit_id);
+CREATE INDEX idx_course_units_order     ON course_units (order_index);
+
+CREATE TABLE unit_lessons (
+  unit_lesson_id BIGINT       GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  unit_id        BIGINT       NOT NULL REFERENCES units   (unit_id)   ON DELETE CASCADE,
+  lesson_id      BIGINT       NOT NULL REFERENCES lessons (lesson_id) ON DELETE CASCADE,
+  order_index    INTEGER      NOT NULL DEFAULT 0,
+  "createdBy"    BIGINT       NULL,
+  "updatedBy"    BIGINT       NULL,
+  "createdAt"    TIMESTAMPTZ  NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  "updatedAt"    TIMESTAMPTZ  NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  CONSTRAINT uq_unit_lessons_unit_lesson UNIQUE (unit_id, lesson_id)
+);
+
+CREATE INDEX idx_unit_lessons_unit_id   ON unit_lessons (unit_id);
+CREATE INDEX idx_unit_lessons_lesson_id ON unit_lessons (lesson_id);
+CREATE INDEX idx_unit_lessons_order     ON unit_lessons (order_index);
+
+-- ── 2. Backfill from the old direct FKs (preserves ordering) ─────────────────
+
+INSERT INTO course_units (course_id, unit_id, order_index, "createdBy", "createdAt", "updatedAt")
+SELECT u.course_id, u.unit_id, COALESCE(u.order_index, 0), u."createdBy", CURRENT_TIMESTAMP, CURRENT_TIMESTAMP
+FROM units u
+WHERE u.course_id IS NOT NULL;
+
+INSERT INTO unit_lessons (unit_id, lesson_id, order_index, "createdBy", "createdAt", "updatedAt")
+SELECT l.unit_id, l.lesson_id, COALESCE(l.order_index, 0), l."createdBy", CURRENT_TIMESTAMP, CURRENT_TIMESTAMP
+FROM lessons l
+WHERE l.unit_id IS NOT NULL;
+
+-- ── 3. Progress tables — standalone reads carry NULL course/unit context ─────
+
+ALTER TABLE unit_reading_progress   ALTER COLUMN course_id DROP NOT NULL;
+ALTER TABLE lesson_reading_progress ALTER COLUMN course_id DROP NOT NULL;
+ALTER TABLE lesson_reading_progress ALTER COLUMN unit_id   DROP NOT NULL;
+
+-- ── 4. Drop the old FK + order columns ───────────────────────────────────────
+-- (dependent indexes/constraints on these columns are dropped automatically)
+
+ALTER TABLE units   DROP COLUMN course_id;
+ALTER TABLE units   DROP COLUMN order_index;
+ALTER TABLE lessons DROP COLUMN unit_id;
+ALTER TABLE lessons DROP COLUMN order_index;
+
+COMMIT;
+
+-- ── Sanity checks (run after commit) ─────────────────────────────────────────
+-- SELECT COUNT(*) FROM course_units;   -- should equal old COUNT(*) FROM units WHERE course_id IS NOT NULL
+-- SELECT COUNT(*) FROM unit_lessons;   -- should equal old COUNT(*) FROM lessons WHERE unit_id IS NOT NULL
+-- SELECT c.title, u.title, cu.order_index FROM course_units cu
+--   JOIN courses c USING (course_id) JOIN units u USING (unit_id)
+--   ORDER BY c.title, cu.order_index LIMIT 20;