How to Secure Your Database with Row Level Security
What row level security actually does, how to write policies that work, and how to prove your data is not exposed.
Written and reviewed by Lovable Student — Independent guides, prompts and troubleshooting notes for people building with Lovable. Expert build help provided by PromptSites.com.
Published 24 Aug 2026 · Tested with Lovable as of 24 Aug 2026
Overview
Row level security decides, per row, who is allowed to read or change it. Without policies, a table is either unreachable or wide open.
Beginner explanation: It is a bouncer standing next to every row, checking who is asking.
Technical explanation: Enable RLS, grant the right table privileges, then write policies scoped to the signed-in user. Check role membership through a security-definer function rather than a subquery that can recurse.
Steps
- Confirm RLS is enabled on every table holding real data.
- Grant table privileges to the roles your policies allow.
- Write a read policy scoped to the owning user.
- Write separate write policies — being able to insert is not permission to read.
- Test with two different accounts.
:::tip Test with a second account, not just signed out. Cross-user leaks only show up with two real users. :::
What to check afterwards
- User A cannot read user B rows
- Signed-out visitors see only public data
- Every table with real data has RLS enabled
Common problems
- RLS on but no policies. Everything fails.
- Privileges missing. Permission errors even with correct policies.
- A policy of "true" for convenience. That is no protection at all.
Where people get stuck
If you have followed the steps and the result still is not right, the fastest path is usually to describe the exact behaviour you expected, the behaviour you got, and any error text, then ask for a fix in one focused follow-up prompt. If that loop is not converging, hand it over.
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Related questions
- AnswerHow do I check Supabase RLS?Ask Lovable to list every table and its row-level security status and policies in plain language — Lovable Cloud users don't have Supabase dashboard access, so this has to go through chat.
- AnswerIs my Supabase anon key safe to expose?Yes. The Supabase anon key is meant to be public — it identifies your project, it does not grant access on its own. Access is controlled by row-level security (RLS) policies, not by hiding the key.
- GuideHow to Store API Keys SecurelyWhich keys are safe in code, which must be secrets, and how to tell the difference.
You might also need
- PromptAudit My Project for Security ProblemsA structured security review covering keys, access rules, roles and server-side checks.
- AnswerHow do I protect API keys?Never put API keys in front-end code — store them as secrets used only inside server functions (Edge Functions), where the browser never sees them.
- AnswerCan users access my database?Only through the access rules you (or your row-level security policies) allow — Lovable Cloud's database isn't publicly browsable, but a table without RLS enabled is effectively open to anyone with your app's public key.
- AnswerWhere should secrets be stored?In your project's server-side secrets store, used only inside Edge Functions — never in front-end code, client-side environment variables, or committed to your Git repository.
