SQL

SELECT, JOINs, aggregates, subqueries, DDL, and indexing—SQL exercises with sample schemas.

224 problems in 7 categories

SQL — SELECT basics

SQL — WHERE & filtering

SQL — JOINs

SQL — Aggregates & GROUP BY

SQL — Subqueries

SQL — DDL & constraints

SQL — Indexes & performance

Toolliyo Assistant

Ask about tutorials, ebooks, training, pricing, mentor services, and support. I use public site content only—not admin or internal tools.

care@toolliyo.com