Essential SQL skills required to become an SQL developer:
- SQL performance tuning
- SQL design skills
- An understanding of the relational theory
- SQL refactoring skills
- Experience with XSLT, Functional programming, NoSQL technologies
- Set theory
- Knowledge about window functions and CTE
If you want to become an SQL Developer, check out this SQL Training course by Intellipaat.
Also, watch this video on SQL Developer for more information: