All SQL practice paths

Pick the career path you want to practice

Each path drops you into a different industry with its own database, stakeholders, and messy-data traps. Pick one to start, or try them all — your progress carries over between paths when you’re signed in.

22 paths · 580 missions · Real stakeholder briefs

Marketing Analytics

Query campaign data, measure ROI, and debug data quality issues for your marketing team.

30 missions|5 tables
  • What campaigns are running?
  • Which campaign drove the most revenue?
  • Normalize the gender mess
  • Real-World ScenariosSolve marketing analytics problems from fictional managers, just like a real job.
  • Messy DataWork with NULLs, duplicates, inconsistent formats, and refunds — the stuff tutorials skip.
  • Instant Feedback5-tier validation engine compares your results against multiple accepted approaches.

Business Intelligence

Build executive dashboards, track KPIs, and translate business questions into SQL.

31 missions|5 tables
  • Who is hitting their sales targets?
  • Rank the sales team
  • Three-table join: who sold what where?
  • Dimensional Modeling in PracticeA 5-table star schema (fact_sales, fact_targets + 3 dimensions) with trailing spaces, ghost regions, inactive employees, and casing drift — the exact patterns you’ll handle modeling real marts.
  • Window Functions End-to-EndRANK, ROW_NUMBER, LAG, LEAD, NTILE, PERCENT_RANK, SUM() OVER with framed windows, moving averages, YoY pivots, and running totals — the window-function curriculum most interviews screen on.
  • Grain Reasoning & Fan-Out BugsMission 26 (“Why is our leaderboard off by 12x?”) drills the canonical BI mistake: a clean query, the wrong grain, a 12× inflated total. Pre-aggregated CTEs as the fix.

Provider Analytics

Query hospital operations data, investigate quality metrics, and build CMS-ready reports for the board.

30 missions|5 tables
  • How many departments do we have?
  • Average length of stay by department
  • Month-over-month encounter trend
  • Real Hospital ScenariosAnswer questions from the CMO, VP of Operations, and CEO about readmissions, wait times, and patient outcomes.
  • EHR Data Quality IssuesDuplicate patients, inconsistent department names, mixed date formats, and bad values that silently break your analysis.
  • Provider-Specific SkillsReadmission rates, length of stay, ED throughput, utilization, CMS methodology, and age bucketing from DOB.

Clinical Operations Analytics

Practice the SQL patterns hospital hiring managers actually recognize: ICD-10 ↔ CCSR terminology joins, principal vs. secondary diagnosis logic, POA gotchas, HCC risk tiering, and the LEFT-JOIN-vs-INNER-JOIN trap that silently breaks production healthcare dashboards. Curriculum modeled on the patterns named in CMS-HCC, AHRQ CCSR, and the Tuva Project.

25 missions|7 tables
  • Pull the chronic disease list
  • Top 3 codes per body system
  • Department CCSR concentration (HHI)
  • Real Terminology JoinsPractice ICD-10 → CCSR → HCC the way Cogito and Caboodle analysts do — the foundational pattern absent from every other SQL learning platform.
  • Principal vs. Secondary LogicCohort patients by principal diagnosis, aggregate comorbidities on those encounters — the HCC-recapture pattern run quarterly at every ACO and Medicare Advantage plan.
  • Production-Grade GotchasPOA NULL handling, ICD-9 legacy detection, and the LEFT-JOIN-vs-INNER-JOIN trap that’s the #1 silent bug in healthcare reporting.

Clinical Trials & Research Analytics

Practice the SQL patterns clinical research analysts and trial sponsors actually run: enrollment cohort analysis, arm balance checks, MedDRA-coded adverse event signal detection, visit adherence drift, and Kaplan-Meier-style retention curves. Real-world terminology — NCT-format trial IDs, CTCAE v5 severity grades 1-5, ATC drug classes, and MedDRA Preferred Terms — on a fully isolated 7-table dataset modeled on real phase 2 / phase 3 protocols.

25 missions|7 tables
  • Enrollments per site
  • First adverse event per enrollment
  • Site HHI — concentration of enrollments per therapeutic area
  • Authentic Trial TerminologyNCT-format trial IDs, MedDRA Preferred Terms for adverse events, CTCAE v5 severity grades, ATC drug classes. The vocabulary every clinical research analyst, biostatistician, and trial sponsor uses daily.
  • Protocol & Cohort AnalysisArm balance checks, screen-fail rates, eligibility strata, and per-arm safety comparisons — the SQL patterns that drive every interim analysis and DSMB report.
  • Safety Signal DetectionSeverity-by-arm cross-tabs, drug-vs-placebo AE rate deltas, and SAE cohort intersection — the analytics that flag a signal before the next protocol amendment.

Payer Claims & Appeals Analytics

Practice the SQL patterns payer claims and appeals analysts actually run: denial rate by CPT, CARC/RARC code frequency analysis, appeal-overturn pivots by level, out-of-network leakage cohorts, and provider-scorecard composites against a real-shape claims ledger. X12 835 standard codes, plan metal tiers, and the adjudication patterns every health-plan analytics team writes daily.

25 missions|6 tables
  • Claims volume by service month
  • Provider denial-rate outliers (specialty-adjusted)
  • Provider appeal-success ranking within specialty (RANK PARTITION)
  • Authentic Payer TerminologyX12 835 CARC and RARC denial codes, CPT procedure codes, place-of-service, plan metal tiers (Bronze/Silver/Gold/Platinum), and HMO/PPO/EPO plan types. The vocabulary every claims analyst, appeals coordinator, and payer revenue-integrity team uses daily.
  • Denial & Appeal MechanicsDenial rate by CPT, CARC frequency × category cross-tabs, overturn% by appeal level, and turnaround-time percentiles — the SQL patterns that drive every monthly denial-management review.
  • Network Leakage & AdequacyOut-of-network provider cohorts via anti-join, network adequacy gaps by specialty × region, and provider denial-rate outliers (specialty-adjusted) — the analytics that surface contracting and access risks.

Pharma Commercial Analytics

Practice the SQL patterns pharma commercial analysts run at Pfizer / Lilly / Novartis / Veeva: top prescribers by NRx, decile-based HCP segmentation, NRx vs TRx breakdowns, call-to-Rx attribution lag, territory market share HHI, switcher cohorts, persistence curves, and brand-launch performance scorecards. Per-Rx-claim grain on 24 months of data spanning a single-brand launch + in-class competitors. The patterns life-sciences commercial teams interview on.

25 missions|7 tables
  • HCPs in cardiology specialty
  • Decile-based prescriber tiers — recompute from Rx volume
  • Territory market share HHI — concentration of Rx volume
  • Authentic Pharma Commercial SchemaPer-Rx-claim grain (NRx vs TRx flag, days_supply, copay), HCP/NPI dimension with decile + target flag + specialty, rep activity with sample drops, payer plans by formulary tier, and normalized territory FK that mirrors how real IQVIA / Veeva / Komodo datasets are shaped.
  • Launch + Competitor NarrativeSingle launch brand (Cardiozin, a new statin) entered market month 17 of a 24-month window; 2-3 in-class competitors hold incumbent share; 5-6 unrelated products provide portfolio breadth. Every mission can hook into 'how is our launch tracking vs. competition?' — the same question every brand team asks every Monday.
  • NRx, TRx & PersistencePer-fill is_new_rx flag enables the canonical NRx (new prescriptions) vs TRx (total prescriptions including refills) split that drives every commercial dashboard. Days-supply distributions, refill-rate cohorts, and time-to-discontinuation curves — the patterns brand teams use to detect adherence and switching.

Hospital Revenue Cycle Management

Practice the SQL patterns hospital RCM analysts run at HCA / CommonSpirit / Epic shops / Athena: denial rate by CPT, days-in-AR by payer, first-pass yield, contractual underpayment detection, claim-to-remit lag, AR aging buckets, and provider productivity vs collections matrices. Per-charge / per-claim / per-remit grain on 24 months of provider-side billing data with planted denial cohorts and underpayment traps. The patterns billing analysts, denials specialists, and CFOs actually run.

25 missions|7 tables
  • Medicare patients by demographic
  • Days-in-AR by payer — open claims aging
  • Payer concentration HHI per service line
  • Authentic RCM SchemaPer-charge / per-claim / per-remit grain mirroring how Epic Resolute, Athenahealth, and Cerner billing systems shape data. Patient and payer dims with primary/secondary insurance attribution, provider dim with department + credentialing flag, CPT charge-master with RVU, claim status transitions (submitted → paid / denied / appealed / closed), and remit-level allowed/paid/adjustment splits with denial codes.
  • Denial + AR Workflow NarrativePlanted denial cohorts (timely-filing, prior-auth, medical-necessity, coordination-of-benefits) drive the denials-management missions. Contractual underpayment plants test the M14 expected-vs-paid detection. AR aging follows realistic 0-30 / 31-60 / 61-90 / 90+ bucket distributions across payer mix.
  • Real RCM KPIsClean Claim Rate (first-pass yield), Days in AR, denial rate by CPT and payer, contractual yield, write-off rate, and the provider productivity views that surface the difference between high-volume billers and high-collections billers.

Finance Data Analyst

Write the variance bridges, P&L rollups, and cash-burn queries tech FP&A teams gatekeep on.

30 missions|5 tables
  • Cost-center ownership map
  • March budget-variance check
  • YoY revenue growth by month
  • Finance Deliverable ScenariosAnswer questions from the CFO, FP&A Manager, Treasury Analyst, Controller, and Senior Auditor — MBR variance packs, budget attainment, revenue seasonality, cash burn, and vendor concentration.
  • Messy Ledger DataDuplicate vendors, un-posted journal entries, inconsistent account-type casing, refund leakage, and duplicate payments — the reconciliation traps that quietly wreck a variance narrative.
  • Finance Analyst SQL SkillsA vs B vs F vs PY variance, gross margin decomposition, running cash burn, YoY revenue growth, percentile ranking, cohort onboarding, and late-posting analysis.

Credit Risk & Banking

Vintage curves, roll rates, fraud rules, and CECL loss projections — the SQL Cap One and bank risk teams interview on.

30 missions|5 tables
  • What products do we book?
  • Monthly net charge-off rate by product
  • Rolling velocity — ≥5 auths in 10 minutes
  • Credit Risk MechanicsVintage analysis, roll rates, delinquency bucketing, FICO-band segmentation, and PD/LGD/EAD feature engineering — the queries every credit analyst writes.
  • Fraud + AML PatternsVelocity features, structuring detection, rolling-window rules, and composite risk scoring — patterned on NICE Actimize / SAS AML / FICO Falcon workflows.
  • Regulatory ReportingPoint-in-time quarter-end snapshots, Y-9C / Call-Report-style aggregations, CECL lifetime-loss projection, and PSI / KS model-monitoring queries.

AML & Fraud Analytics

Structuring detection, velocity windows, entity resolution, and rule-tuning backtests — the SQL AML analysts and fraud strategists actually write.

30 missions|6 tables
  • What channels do we see?
  • Round-dollar wires — flag a pattern
  • Alert precision — how good is our rule?
  • Real AML TypologiesStructuring below the $10K CTR threshold, smurfing across multiple accounts, round-dollar wire cycles, dormant-then-active money mules, and device/IP/email reuse across “separate” customers — every FinCEN / FATF / Wolfsberg pattern maps to a mission.
  • Velocity + Self-Join SQLCOUNT() OVER with date-range window frames, correlated subqueries for same-counterparty pairs, SOUNDEX / LEVENSHTEIN for entity resolution, and gap-and-island logic for dormant account reactivation.
  • Rule Tuning + BacktestingBacktest a proposed threshold against historical alerts, compute rule precision / recall on true-positive labels, and measure false-positive reduction — the analysis every compliance team asks of new hires.

Retail Banking Operations

The retail-banking analyst role at a regional or money-center bank: deposit growth decomposition, deposit beta on MMAs, NSF/OD fee revenue post-CFPB, branch consolidation scoring, NII decomposition, primary-banking-relationship classification, churn leading indicators, and FTP-allocated branch P&Ls against a realistic retail bank with planted reconciliation traps.

30 missions|11 tables
  • Product taxonomy inventory
  • Deposit beta on MMAs (cycle-to-date)
  • 2025 closed-account exit cohort with tenure
  • Retail Banking ScenariosAnswer questions from the Retail COO, Branch Ops Manager, Treasurer, and Customer Insights Lead — weekly retail dashboards, ALCO-ready deposit beta, NSF/OD scenario modeling, and branch P&L with FTP allocation.
  • Authentic Retail Bank Schema6-table retail_* core (customers, accounts, products, branches, transactions, daily balances) plus retailops_* specialty tables for branch activity, fees, and ATM events. Numbers anchor to 2024-2026 retail banking realities.
  • Deposit + Branch + Treasury + Customer SkillsAverage daily balance, weighted deposit beta, primary-relationship EXISTS logic, churn lag features, FTP curve allocation, and the multi-CTE rollups that real retail-bank dashboards run on.

Consumer Lending Analyst

The consumer-lending analyst role at a regional or money-center bank: HMDA action-taken decomposition, fair-lending disparity analysis, vintage curves and first-payment-default cohorts, ARM reset wall identification, refi candidate targeting, delinquency aging and roll rates, charge-off recovery, CECL-style loss reserve decomposition, and ALCO-ready portfolio stratification — against a realistic mortgage / auto / HELOC / personal lending dataset with planted HMDA and servicing reconciliation traps.

30 missions|8 tables
  • Loan product taxonomy
  • Approval rate by FICO band
  • Refi candidate cohort
  • Consumer Lending ScenariosAnswer questions from the Chief Credit Officer, Mortgage Sales Director, Fair Lending Compliance Officer, and Loan Servicing Lead — weekly origination dashboards, HMDA LAR reconstructions, ARM reset walls, and CECL-style loss reserves.
  • Authentic Lending Schemalending_applications (HMDA-shaped), lending_originations (funded loans with FICO/DTI/LTV at orig), lending_payments (past installments with days_late), and lending_geography (census tract + LMI). Joins to the shared retail_* core for customer demographics.
  • HMDA + Vintage + Servicing SkillsHMDA action-taken decomposition, denial-reason rollups, LMI-tract approval gap analysis, vintage curves with cohort EXISTS, ARM reset arithmetic, roll-rate matrices, charge-off recovery ratios, and the multi-CTE rollups that real credit teams ship.

RevOps & Sales Analytics

OpportunityHistory SCD2, Closed-Won reopens, stage regressions, forecast accuracy, ARR waterfalls — the SQL RevOps and Sales Ops analysts actually write.

34 missions|8 tables
  • What stages exist in the pipeline?
  • Deals that reopened after Closed-Won
  • Closed-Won cohort retention by month
  • Salesforce-Shaped SchemaAccount, Contact, Lead, Opportunity, OpportunityHistory, User. The exact table shape you’ll see on day one of any Sales Cloud shop, with the field names you’ll recognize from real Salesforce exports.
  • OpportunityHistory SCD2Every stage change, amount change, owner change logged as a row. Point-in-time reconstruction (“what did the forecast look like on March 15?”), stage regression detection, and the Closed-Won reopen anti-pattern that invalidates 80% of naive pipeline reports.
  • Sales Cycle + Velocity SQLStage-duration windows, rep win-rate by region, top-N per group, quarter-over-quarter bookings waterfalls, forecast accuracy as a backtest. The full RevOps analyst toolkit.

E-commerce & Retail Analytics

Shopify-vs-Stripe-vs-GA4 reconciliation, refund-aware revenue, RFM segmentation, repeat-purchase cohorts — the SQL DTC and retail analysts actually write.

30 missions|6 tables
  • What financial statuses exist?
  • Top 10 products by units sold
  • Repeat-purchase cohort retention
  • Shopify-Shaped SchemaCustomers, products, orders, line items, with the financial_status / fulfillment_status fields you’ll see on day one of any DTC shop. Familiar to anyone who’s opened a Shopify export.
  • Three-System ReconciliationGA4 sessions and Stripe charges sit alongside Shopify orders with planted mismatches — partial refunds, currency conversion fees, failed captures, GA4 conversion-value drift. The signature mission ties all three together.
  • Refund + Cohort + RFM SQLRefund-aware revenue, repeat-purchase cohorts, RFM segmentation, abandoned-cart funnels, source/medium attribution. The full DTC analyst toolkit.

Operations & Supply Chain Analytics

SQL for ops & supply-chain analysts — inventory turns, on-time delivery, supplier scorecards, demand-forecast variance.

30 missions|7 tables
  • Show me the warehouses
  • Average lead time per supplier
  • Demand week-over-week change
  • Real Supplier ScorecardsOn-time delivery, lead time, and chronic-late-shipment patterns across 8 suppliers and a ghost row.
  • Inventory Health QueriesLatest-snapshot dedup, days-of-supply alerts, stock-out risk — the queries warehouse leads run every morning.
  • Demand vs PlanMAPE forecast accuracy, the S&OP-review metric every demand planner ships weekly.

Logistics & Transportation Analytics

Carrier OTIF, freight invoice audits, detention hot spots, cost-per-unit benchmarking, and multi-metric carrier scorecards — the full logistics & transportation analyst SQL curriculum across 30 missions.

30 missions|5 tables
  • Meet the carrier network
  • Monthly shipment volume trend
  • Carrier OTD vs. target gap
  • OTIF Compound MetricBuild the on-time AND in-full formula at PO-line grain — the exact logic Walmart enforces with a 3% COGS chargeback.
  • Freight Invoice AuditsFind overbilled invoices, accessorial overcharges, and contract rate violations across carriers and lanes.
  • Detention AnalysisIdentify facilities where dwell time exceeds 2 hours on more than a third of shipments — the hidden cost every logistics manager wants to cut.

Procurement & Sourcing Analytics

PO cycle time analysis, purchase price variance, maverick spend detection, three-way match exceptions, and supplier risk scorecards — the full procurement & sourcing analyst SQL curriculum across 30 missions.

30 missions|6 tables
  • Category catalog
  • Top 10 suppliers by spend
  • Contract compliance rate
  • PO Lifecycle AnalysisTrace the full req → PO → ASN → receipt → invoice cycle and measure cycle time at every stage.
  • Purchase Price VarianceCompare actual vs contracted unit price to surface PPV exceedances by category — the metric that drives finance escalations.
  • Maverick Spend DetectionFind POs with no contract_id — off-contract spend that bypasses negotiated pricing.

Warehouse Operations Analytics

Units per labor hour, dock-to-stock decomposition, pick accuracy by zone, slotting recommendations, and wave analysis — the full warehouse operations analyst SQL curriculum across 30 missions.

30 missions|7 tables
  • Worker roster
  • Pick accuracy
  • Labor by function
  • UPLH by Zone and ShiftCompute units per labor hour across picking zones and shifts — the metric DC managers review every morning.
  • Dock-to-Stock DecompositionBreak the inbound cycle into unload, count, and putaway phases to find the bottleneck causing SLA breaches.
  • Pick Accuracy Heat MapRank zones by pick error rate — surface the OVERFLOW zone pattern where error rates are 4× higher than GOLDEN.

Demand Planning & Forecasting Analytics

WMAPE calculation, forecast bias detection, tracking signal computation, consensus vs statistical forecast value-add, promo lift attribution, and ABC×XYZ segmentation — the full demand planning analyst SQL curriculum across 30 missions.

30 missions|6 tables
  • Location count
  • WMAPE
  • Forecast value-add
  • WMAPE vs MAPELearn why WMAPE (Σ|A−F|/ΣA) is the industry default — it weights by volume and avoids divide-by-zero on intermittent SKUs.
  • Forecast Bias DetectionSpot the systematic over-forecast on Category C that hides inside an acceptable WMAPE — the pattern demand planners escalate to leadership.
  • Tracking SignalCompute rolling tracking signals and flag SKUs where |TS| > 4 — the statistical trigger for model recalibration.
Coming soon

People Analytics

SQL for People Analytics — hiring funnel, attrition, comp bands, manager span of control, engagement scorecards.

0 missions|0 tables
  • Recruiting FunnelStage-to-stage conversion, time-to-fill, source-of-hire mix.
  • Attrition AnalysisVoluntary vs involuntary, regrettable cohorts, tenure curves.
  • CompensationPay-band drift, internal equity, merit-cycle modeling.
Coming soon

IT & DevOps Analytics

SQL for IT / DevOps / Security — incident MTTR, DORA metrics, ticket SLA, vulnerability burn-down.

0 missions|0 tables
  • Incident AnalyticsMTTR, MTBF, severity-mix, repeat-incident clustering.
  • DORA MetricsDeploy frequency, lead time for changes, change-failure rate.
  • Service DeskTicket SLA attainment, queue aging, first-contact resolution.