Supabase Database

Project schema, roles, migration history, auth flow, and key files: supabase-config.md. Docs: https://supabase.com/docs

RLS gotchas

• ENABLE ROW LEVEL SECURITY with no policy denies everything. Enabling and adding policies must land in the same migration.
• Policies are per-operation. FOR SELECT USING (...) does not cover writes; INSERT needs WITH CHECK, not USING.
• auth.uid() is the owner check (auth.uid() = id). It is NULL for the anon role, so any policy relying on it silently blocks anonymous access.
• Test every policy against all three roles — anon, user, admin. A policy that works as your own user tells you nothing about anon.
• Reference auth.users(id) with ON DELETE CASCADE on profile-style tables, or deleted users leave orphans.

Confirm RLS coverage before shipping:

SELECT tablename, rowsecurity FROM pg_tables WHERE schemaname = 'public';

Migration workflow

1. Name migrations YYYYMMDD_add_profiles.sql; comment intent and rollback considerations inline.
2. Apply to a local/ephemeral DB; run smoke tests plus per-role RLS checks.
3. Review the SQL for destructive actions (table drops, column rewrites) — those need a backfill script and phased rollout, never a single migration.
4. Re-run in CI against a test replica with the full suite.
5. Deploy via the safe-deploy pipeline, then re-verify RLS, indexes, and a data sanity query.

Regenerate types after every schema change (CI step):

supabase gen types typescript --project-id <project-id> > src/types/supabase.ts

Assert at steps 2 and 4 that the migration completes, per-role RLS queries still pass, and tests on changed paths pass. On failure: revert, adjust, re-run.