W3Schools SQL Tutorial: W3Schools provides a comprehensive tutorial on SQL that covers the basics as well as advanced topics. It also offers interactive exercises to practice your SQL skills.

SQLZoo: SQLZoo is a popular online platform for learning SQL through interactive exercises and quizzes. It covers various SQL dialects such as MySQL, PostgreSQL, and SQL Server.

SQL for Web Developers: This course on Udemy covers SQL basics and advanced topics for web developers. It also includes hands-on projects to apply your SQL skills.

SQL Dialects: A Quick Reference: This book by Alex Kriegel provides a quick reference guide for different SQL dialects including Oracle, MySQL, PostgreSQL, and SQL Server. It covers syntax, functions, and features specific to each dialect.

SQL Performance Explained: This book by Markus Winand focuses on optimizing SQL queries for different database systems including Oracle, MySQL, PostgreSQL, and SQL Server. It covers best practices and performance tuning techniques for each SQL dialect.

SQL Cookbook: This book by Anthony Molinaro provides solutions to common SQL problems using various SQL dialects. It covers a wide range of topics from basic queries to advanced data manipulation techniques.