Import the DDL you copy from Postgres or Supabase. No backend, no sign-up.
CREATE TABLE users (
id uuid PRIMARY KEY,
email text UNIQUE,
name text
);
CREATE TABLE posts (
id uuid PRIMARY KEY,
user_id uuid REFERENCES users,
title text
);
Interactive diagram
Draggable cards with column types and keys.
Anti-patterns
Unindexed FKs, tables without a PK, types without length.
3 WARN
Foreign-key live
Select a table and see what it references and what references it.