Answer product questions with SQL you can defend.
Rated 4.7 (3)
SQL is still the shortest path from a question to an answer. We stay in real tables: joins you can explain, windows you actually need, and queries a teammate can read.
2 sections · 4 lessons
1. The question
Preview: what a clean warehouse actually looks like.
1.2 Joins you can explain
If you cannot draw it, do not ship it.
2. The answer
2.1 Windows without folklore
Running totals, ranks, and the few you need.
2.2 A brief you can hand over
Write the query as a sentence first.
Rated 4.7 (3)
Owen Fraser
Jul 8, 2026
Rated 5.0
Practical from the first lesson. No folklore.
Hannah Cole
Jul 4, 2026
Rated 4.0
Windows section is worth replaying.
Mateo Ruiz
Jul 1, 2026
Rated 5.0
I can hand a query to a teammate without a second document.