The latest articles on DEV Community by Amjad (@amjad_40b317ac5b1a010b526). https://dev.to/amjad_40b317ac5b1a010b526 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3997946%2Fec58b2c2-4739-4a33-a7b0-46bd159454ee.png https://dev.to/amjad_40b317ac5b1a010b526 en Amjad Tue, 23 Jun 2026 04:49:30 +0000 https://dev.to/amjad_40b317ac5b1a010b526/i-built-a-free-tool-that-turns-sql-schemas-into-er-diagrams-no-signup-needed-2pbg https://dev.to/amjad_40b317ac5b1a010b526/i-built-a-free-tool-that-turns-sql-schemas-into-er-diagrams-no-signup-needed-2pbg <h2> What I built </h2> <p>DevForge is a free SQL schema visualizer - paste your Postgres <br> CREATE TABLE statements and instantly get a clean visual ER diagram <br> showing your tables, columns, primary keys, foreign keys, and <br> relationships between them.</p> <p>No account needed. Just paste and generate.</p> <p>Try it here: <a href="https://devforge-sql.vercel.app" rel="noopener noreferrer">https://devforge-sql.vercel.app</a></p> <h2> Why I built it </h2> <p>I kept wanting to quickly visualize database schemas while learning <br> SQL and building projects, but existing tools were either too complex, <br> required signups, or didn't handle real-world messy schemas well.</p> <h2> What it handles </h2> <ul> <li>Composite primary and foreign keys</li> <li>Array types (TEXT[], NUMERIC(10,2)[])</li> <li>Custom enum/type columns</li> <li>GENERATED ALWAYS AS IDENTITY columns</li> <li>Foreign keys defined via ALTER TABLE (not just inline REFERENCES)</li> <li>Self-referencing tables (tree structures)</li> <li>Circular foreign keys</li> </ul> <h2> Tech stack </h2> <ul> <li>Next.js 14 + TypeScript</li> <li>React Flow (diagram rendering)</li> <li>elkjs (auto-layout - chose this over dagre after a side-by-side crossing-count comparison on a 15-table schema)</li> <li>node-sql-parser (Postgres dialect)</li> <li>Deployed on Vercel free tier</li> </ul> <h2> What I learned building it </h2> <p>The trickiest part was the SQL parser. node-sql-parser only accepts <br> a bare identifier as a column type if that exact name was already <br> declared via CREATE TYPE earlier in the same string. So <code>status <br> order_status</code> would fail unless <code>CREATE TYPE order_status AS ENUM</code> <br> appeared before it. The fix was pre-scanning for undeclared custom <br> types and synthesizing throwaway CREATE TYPE declarations before <br> parsing.</p> <h2> What's next </h2> <p>Currently working on adding auth + save projects, then export <br> (PNG free, PDF paid). Would love any feedback - especially if you <br> throw a real/messy schema at it and something breaks!</p> postgres sql webdev showdev