SQL Practice & Query : queri

Type SQL, run it, see real rows. Practice by writing queries, not by memorising.

queri is a SQL course for people who want hands-on practice, not another multiple-choice quiz. Every lesson ends with a query you write yourself and run against a real database stored on your phone. No signup. Works fully offline.

WHY QUERI IS DIFFERENT
You can pass a quiz about JOINs and still freeze in front of a real table. queri never asks you to recognise SQL. It asks you to write it, runs what you wrote, and checks the rows that came back. That is the difference between reading about a database and using one.

HOW A LESSON WORKS
1. A short, plain-English explanation of one idea. No walls of theory.
2. A real task on a real dataset: "list every customer in New York".
3. You type the query. You run it. You see the actual rows.
4. queri compares your result to the correct one and tells you exactly what is off.
5. Stuck? A hint aimed at your specific mistake, not a generic nudge.

THE FULL SQL COURSE
- SELECT: pull columns out of a table, rename them, remove duplicates
- WHERE: filter with AND, OR, BETWEEN, IN, LIKE and NULL
- ORDER BY and LIMIT: sort and slice your results
- COUNT, SUM, AVG, MIN, MAX: aggregate a column
- GROUP BY: aggregate per group
- JOIN: combine tables, including three-table joins
- A capstone challenge: revenue per customer, written from scratch

These are the exercises that come up in real work and in SQL interview questions, in the order that makes them stick.

A REAL DATABASE, NOT A TOY
You work against a small online-shop database: customers, products, orders and order items, with real rows, real NULLs and real messiness. The schema is one tap away while you write, so you are never guessing at column names.

RUNS ON SQLITE, ON YOUR DEVICE
queri runs a genuine SQLite engine locally. Everything you learn is standard SQL that transfers directly to MySQL, SQLite and any other database you meet later. Because it is all on-device, you can practice on the metro, on a plane or with no signal at all. Nothing is uploaded and there is no account to create.

BUILT FOR A PHONE KEYBOARD
A SQL key row with the characters you actually need. Results in a table you can scroll sideways. Progress and a daily streak saved locally on your device.

SIX LANGUAGES
English, French, Arabic with full right-to-left support, Spanish, Italian and Portuguese.

FREE AND PRO
The first module and the first eight lessons are free, which is enough to know whether this works for you. queri Pro unlocks the full curriculum.

SQL is the one technical skill that outlasts every framework. Learn SQL by writing it.