The 20% of SQL That Does 80% of the Work

Five SQL clauses answer most business questions: SELECT, WHERE, GROUP BY, JOIN and HAVING. But the thing that actually unblocks people isn't the syntax — it's knowing that SQL doesn't execute in the order you write it. This cheat sheet covers the five essential clauses, SQL's true execution order (FROM → WHERE → GROUP BY → HAVING → SELECT → ORDER BY), why WHERE and HAVING aren't interchangeable, and a worked query that uses all of them.

By Ibrahim Denis Fofanah