The SQL 50 on LeetCode provided an extensive collection of SQL problems covering a wide range of concepts and techniques. This challenge included easy, medium and hard level questions from various topics like-
- Selects
- Basic Joins
- Basic Aggregate Functions
- Sorting and grouping
- Advanced Select and joins
- Subqueries
- Advanced String Functions / Regex / Clause
Some of the resources I used in order to learn SQL are –