Hello this is Gulshan Negi
Well, in the last few days, I also searched the internet for SQL courses, and I found many of them there. and one of my friends suggests I go with the courses that are easily available on the udemy or Coursera. and he suggested https://hackr.io/blog/best-sql-courses post, here author listed many of the SQL courses, this list help me a lot. and I bought SQL Tutorial for Beginners - Learn SQL using MySQL by Udemy. this course is very good. and also, I view some of the SQL tutorials on Youtube; there are many Youtube videos there that are very help full for me.
some of them are:
1: SQL tutorial by freecodecamp
2: SQL tutorial by great learning
3: SQL Training by Intellipaaat
and I also bought these books from amazon:
1: Learning SQL by Alan Beaulieu
2: SQL Cookbook by Anthony Molinaro.
3: Head First SQL by Lynn Beighley and Michael Morrison
4: Pro SQL Server Internals by Dmitri Korotkevitch