A Data Science Central Community
As you would know, SQL is essential for many tasks involving working with large quantities of data.
Members of Analytic Bridge might like to download my guide to SQL titled 'SQL Essentials' available for free download from my personal website www.markmcilroy.com
Also on my personal website is a practice SQL environment where you can query a sample database and try out the examples from the book.
This book and my other books are also available in print from Amazon.com