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