SQL DDL DML DCL / TCL Joins Window Fn Aggregates CREATE ALTER DROP / TRUNCATE SELECT INSERT UPDATE / DELETE GRANT REVOKE COMMIT / ROLLBACK INNER LEFT / RIGHT FULL OUTER ROW_NUMBER RANK / DENSE_RANK LAG / LEAD / NTILE AVG / SUM COUNT MIN / MAX

SQL is the one skill that hasn’t gone out of style in 30 years — and probably won’t for another 30. Whether you’re writing a quick SELECT or building a multi-CTE pipeline that feeds a Tableau dashboard, having a mental model of how all the pieces connect is more useful than memorizing syntax.

This mindmap breaks SQL into its core branches:

  • DDL — the structural layer (CREATE, ALTER, DROP, TRUNCATE)
  • DML — the data layer (SELECT, INSERT, UPDATE, DELETE)
  • DCL / TCL — access control (GRANT, REVOKE) and transaction safety (COMMIT, ROLLBACK, SAVEPOINT)
  • Joins — INNER, LEFT, RIGHT, FULL OUTER — the backbone of relational thinking
  • Window Functions — ROW_NUMBER, RANK, DENSE_RANK, LAG, LEAD, NTILE — where analytical SQL really shines
  • Aggregate Functions — AVG, SUM, COUNT, MIN, MAX — the basics that never stop being useful

I keep this pinned because even after 13 years, I still glance at it when I’m deep in a complex query and need to remember which branch a concept lives on. It’s not about memorization — it’s about having a map so you always know where to look.

If you’re early in your SQL journey, save this. If you’re senior, share it with your team.