Flexible path4 sections

SQL Practical Query Problems

Hands-on SQL rounds built around real product data and production constraints.

A practical SQL interview track covering joins, anti-joins, many-to-many filters, interval overlap, aggregation, fanout-safe totals, window functions, stable pagination, hierarchy queries, SARGable dates, and concurrent updates.

Recommended start

Joins & Filtering

Parent-child queries, anti-joins, many-to-many filters, range overlap, and duplicate-safe result shapes.

5 drillsSection 1 of 4

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Learning path

4 active sections / 19 drills

1Joins & FilteringRecommended startParent-child queries, anti-joins, many-to-many filters, range overlap, and duplicate-safe result shapes.5 drillsSection 1Open section 2Aggregation & ReportingConditional metrics, duplicate detection, fanout-safe totals, and calendar-aware rolling reports.4 drillsSection 2Open section 3Windows & PaginationLatest rows, top-N per group, keyset paging, running totals, streaks, hierarchy paths, and ranking.6 drillsSection 3Open section 4Correctness & PerformanceSARGable time-zone queries, atomic inventory updates, safe deterministic data cleanup, and evidence-led execution-plan diagnosis.4 drillsSection 4Open section