SQL for FE devsFor front-end developers

Notes-style walkthrough of SQL - so APIs, ORMs, and "why is this list slow" stop feeling like magic.

You already know data shapes

Tables ≈ typed collections, rows ≈ objects, JOINs ≈ nested includes. I'll map SQL to the JSON you already fetch every day.

SQLite first

One file DB, zero server drama. Good enough to learn - and the ideas transfer to Postgres / MySQL when you meet them.

CRM as the payoff

We end by designing a small CRM schema - companies, contacts, deals, activities - plus the queries a real UI would need.

Who this is for

I've written this as if I'm leaving notes for myself - a front-end person who knows fetch, filter state, pagination, and nested API payloads… but has mostly treated the database as "backend stuff".

If you've shipped React/Vue/Svelte and you want to understand what sits under /api/contacts?page=2&q=ada, you're in the right place.

How to follow along

Install SQLite (Setup)
Read chapters in order - later ones assume earlier mental models
Run the CRM bits from examples/crm/ when we get there
Keep the cheatsheet open once you're past the query core

bash

npm install
npm run docs:dev

And for SQL bits:

bash

sqlite3 examples/crm/crm.db < examples/crm/schema.sql

What's intentionally missing

Deep Postgres tuning / replication / partitioning
Full ORM frameworks (Prisma, Eloquent, etc.) - we peek, we don't marry them
Fancy window functions as a lifestyle

We're here for reading SQL confidently and designing a schema that matches a UI you might actually build.

Wish you all the best - hope you're gonna enjoy the ride.

Best,

-- ł.