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New: Practice SQL in realistic company scenarios

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Exercises

High-Value Orders ReportEasy Promotion-Eligible ProductsEasy Gmail Customers for Migration NoticeEasy Premium Catalog by PriceEasy Recent Activity WidgetEasy At-Risk Premium CustomersEasy Filtered Product CatalogEasy

Count Orders and Unique CustomersEasy Monthly Revenue and Average Order ValueEasy Cheapest and Most Expensive Products by CategoryEasy Revenue Breakdown by Product CategoryEasy Order Counts by Country and MonthEasy Premium Supplier Program CategoriesEasy High-Volume Categories Excluding Small OrdersEasy

Shipping Labels with Customer NamesEasy Total Spend per CustomerEasy Customer Order Count Including InactiveEasy Find Products Never OrderedEasy Premium Customer Recent OrdersEasy Average Order Value by Product CategoryEasy Customer Summary ReportEasy

Flag Products Missing DescriptionsEasy Clean Up NULL Categories for ReportingEasy Classify Orders by Shipping TierEasy Monthly Order Size DistributionEasy Customer Health Score ClassificationEasy

Comprehensive Order ReportMedium Employee-Manager DirectoryMedium Revenue Breakdown by Product CategoryMedium Find Missing Products in StoresMedium Same-Category Price ComparisonsMedium Top Performers Across DepartmentsMedium E-commerce Executive Summary PipelineMedium

High-Value Invoices Above AverageMedium Most Recent Order per CustomerMedium Monthly Revenue by Plan TierMedium Customer Segmentation for MarketingMedium Products Never OrderedMedium Month-over-Month Revenue GrowthMedium SaaS KPI Dashboard PipelineMedium Employee HierarchyHard Date Series GenerationMedium

Top N Per GroupMedium Number Orders ChronologicallyMedium Sales Ranking with TiesMedium Customer Spending QuartilesMedium Salary Percentile RankingMedium Deduplicate Customer AddressesMedium Top Salesperson Per Region Per QuarterMedium RFM Customer SegmentationHard

Year-over-Year GrowthHard Previous Month Revenue ComparisonMedium Next Appointment SchedulingMedium Month-over-Month User Signup GrowthMedium First and Last Purchase Per CustomerMedium Same Month Last Year ComparisonHard Detect Consecutive Sales DeclineHard

Find Inactive CustomersEasy

I6 — Date & String FunctionsComing Soon

I7 — Conditional AggregationComing Soon

Running Total & Moving AverageMedium Cumulative User SignupsHard ROWS vs RANGE Frame ComparisonHard Cumulative Spending Per CustomerHard Revenue Target Progress TrackingHard

Login Streaks (Gap & Island)Hard Consecutive Active DaysMedium Group Consecutive Active Days into RangesHard Find Missing Invoice NumbersHard Sessionize Page ViewsHard

Cohort Retention AnalysisHard

Funnel AnalysisHard

A5 — Revenue Metrics (MRR/LTV)Coming Soon

A6 — PIVOT / UNPIVOTComing Soon

A7 — DuckDB Modern SQLComing Soon

A8 — Advanced Business ScenariosComing Soon

Other Exercises

Order Dataset OverviewEasy Customer Contact ListEasy Product Category InventoryEasy Data Quality SnapshotEasy Clean Report HeadersEasy Q4 Orders for Year-End ReportEasy Customers Missing Phone NumbersEasy Top 5 Revenue-Generating ProductsEasy Lowest Rated Products to ReviewEasy Employee Directory by Department then NameEasy Order Status DistributionEasy High-Volume Product CategoriesEasy Match Employees with DepartmentsMedium Monthly Sales BreakdownMedium Average Delivery Time per RegionMedium Clean Product Names for CatalogMedium Extract Email DomainsMedium Quarterly Revenue ReportMedium Fill Missing Prices with Category AverageMedium Deduplicate Customer RecordsMedium Replace Sentinel Values (-1, N/A)Medium Revenue Share per CategoryMedium Sales KPI Summary per RegionMedium Order Status by RegionMedium Monthly Revenue by CategoryMedium Unpivot Quarterly MetricsMedium Sales Summary with TotalsMedium Flatten Multi-level GroupByMedium Customer Segment vs Product AffinityMedium Month-over-Month Growth RateHard Compare Each Month to PreviousHard All-Time Revenue HighHard Find Missing Days in Time SeriesHard Session Detection (30min gap)Hard Longest Winning Streak per PlayerHard Combine Monthly ReportsHard Update Master with New DataHard Find Changes Between SnapshotsHard Match Trades to Nearest QuoteHard Replace apply() with Vectorized OpsHard Build ETL Pipeline with pipe()Hard Readable Filters with query()Hard Method Chaining: Clean, Transform, AggregateHard Optimize Memory with CategoriesHard