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Given a multi-table dataset (e.g. orders + customers + products in PostgreSQL/SQLite/DuckDB, or a sample warehouse), answer 4-6 real business questions purely in SQL. Use JOINs to combine tables, GROUP BY/HAVING for aggregation (WHERE to filter rows before grouping), and at least two WINDOW FUNCTIONS (e.g. running total, rank within a group, month-over-month change). Use CTEs to keep multi-step queries readable. For each question, state the question, the query, and the answer in one sentence. Verify a couple of numbers independently.
Queries return the right rows; JOIN types correct; WHERE vs HAVING used correctly; aggregations accurate.
At least two correct window functions; CTEs structure multi-step logic; questions are genuinely business-relevant.
Each question has a one-sentence, decision-useful answer; results sanity-checked.
Queries runnable as-is against a documented schema; numbers can be re-derived.
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# SQL analysis answering business questions ## Goal Given a multi-table dataset (e.g. orders + customers + products in PostgreSQL/SQLite/DuckDB, or a sample warehouse), answer 4-6 real business questions purely in SQL. Use JOINs to combine tables, GROUP BY/HAVING for aggregation (WHERE to filter rows before grouping), and at least two WINDOW FUNCTIONS (e.g. running total, rank within a group, month-over-month change). Use CTEs to keep multi-step queries readable. For each question, state the question, the query, and the answer in one sentence. Verify a couple of numbers independently. ## Acceptance criteria - [ ] SQL correctness: Queries return the right rows; JOIN types correct; WHERE vs HAVING used correctly; aggregations accurate. - [ ] Analytical depth: At least two correct window functions; CTEs structure multi-step logic; questions are genuinely business-relevant. - [ ] Communication: Each question has a one-sentence, decision-useful answer; results sanity-checked. - [ ] Reproducibility: Queries runnable as-is against a documented schema; numbers can be re-derived. ## Verification - [ ] Document installation and run commands. - [ ] Record automated checks and their exact commands. - [ ] Add representative output, screenshots, or a short demo where useful. - [ ] Confirm failure paths and known constraints. ## Decision log ### Decision title - Context: - Choice: - Alternatives considered: - Tradeoffs: ## Evidence - Link each rubric criterion to the file, test, or artifact that demonstrates it. ## Known limitations - List what is intentionally out of scope and what should be improved next.