My exercises with SQL
SQL Interactive Tutorial (RU)
http://sql-tutorial.ru/ru
Visual explanation of JOINs in SQL (RU)
http://vas3k.ru/blog/97/
http://www.tutorialspoint.com/sqlite/sqlite_java.htm
SQL programming: the most comprehensive video course (RU)
https://techrocks.ru/2018/06/28/sql-programming-video-course/