Oracle Database Notes for Professionals

A practical SQL reference built from real questions and answers. Covers SELECT, joins, GROUP BY, subqueries, window functions, indexes, transactions, and stored procedures with short, ready to run examples.

GoalKicker

An open source guide for beginners. You learn to create tables, insert and update data, filter with WHERE, sort and group results, join tables, and back up a MySQL database.

Bobby Iliev

A vendor-neutral course on standard SQL. It starts with the relational model and moves through CREATE TABLE, data types, SELECT, joins, grouping, NULL handling, transactions, and views.

Wikibooks

More than 280 pages of T-SQL tips. Topics include data types, common table expressions, window functions, JSON and XML handling, indexes, stored procedures, triggers, and backup and restore.

GoalKicker