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M0 — SQL Refresh + Skip-Gate
Joins/CTE refresh drill, window-functions article, SQL skip-gate quiz, ecommerce SQL submission.
Module Content
SQL Joins + CTEs Refresh Drill
Outcome: rewrite 3 nested queries with CTEs correctly. Curated video (9:41, verified 2026-09-24 via yt-dlp): Lec-70: WITH Clause in SQL | SQL CTE (Common Table Expression) | DBMS (Gate Smashers) Watch: https://www.youtube.com/watch?v=0vpzgsIS5Lg Notes: WITH-clause syntax; rewriting nested subqueries as named CTEs; chaining CTEs; readability recap. Pair with a joins refresher: INNER/LEFT/RIGHT semantics before attempting the 3-query rewrite drill. Key moments: No chapter markers on source; key beats: WITH syntax intro, nested-to-CTE rewrite demo, readability recap.
Window Functions Drill (rank/lead/lag, frames)
Solve gaps-islands + running-total drills.
Quiz: SQL Skip-Gate
10 scenario MCQs (joins/window/CTEs). Pass >= 80. Exit-battery bank A.
Ecommerce SQL Query Set
Submit 5 correct queries on messy orders data. Dataset + guardrails + 100-pt rubric inside.