Reference library

SQL guides

Focused, maintained SQL explanations that complement the hands-on lesson track.

concepts

SQL Window Functions: Ranking and Running Totals

Use OVER, PARTITION BY, and ORDER BY for rankings and running totals without collapsing detail rows.

For:: SQL learners who know grouping and need analytical queries
Maintained:: 2026-08-14
Version context:: SQLite 3.25+ execution contract; PostgreSQL window syntax is linked below

Related lessons

concepts

Understand SQL's three-valued logic, use IS NULL correctly, and avoid NOT IN and nullable-filter surprises.

For:: SQL learners debugging missing rows and nullable filters
Maintained:: 2026-08-14
Version context:: Standard SQL concepts; executable examples are pinned to SQLite

Related lessons