Focused path · SQL Analyst

SQL 50

50 canonical experiences selected to strengthen foundations, business analysis and window functions. They share progress with the main catalogue.

Progress0 / 500 %
Difficulty15 · 25 · 1015 beginner · 25 intermediate · 10 advanced
Estimated time23 hbased on each exercise’s estimated duration
Skills covered
Precisely define output columnsRespect the order requested by the recipientAvoid SELECT* in a query intended for reuseTranslate a business threshold into a predicate WHEREChoosing between strict superior and superior or equalProduce a repeatable order with ORDER BYEliminate duplicates with DISTINCTSort before limiting

Your practice plan

One clear next step, all the way to 50/50.

Choose your pace. Both modes use the same exercises and shared progress.

Do this nowSelect the correct columns

Show only the name and price of each product.

Start SQL 50 →
SQL 50 progress0 / 50
0 / 50

2 of 50 exercises are open with your current access.

Your successes are saved on this device. Create a free account to sync them and resume anywhere.

SQL 50 milestones

Every success moves your level forward.

0XP earned in SQL 50
Level 1Discovery0 %200 XP to the next level
Next milestoneFirst momentum5 exercises left
  1. First momentum5 / 50
  2. Foundations15 / 50
  3. Connected queries25 / 50
  4. Ready for analysis40 / 50
  5. SQL 50 complete50 / 50

XP is calculated from distinct completed exercises, never from the number of attempts.

1Module 1Read, filter and sortSelect the right rows and make the result reproducible.0 / 7
  1. Select the correct columnsSELECT · Beginner · 15 min
    Do this nowView details
  2. Filter and sort ordersWHERE · ORDER BY · Beginner · 15 min
    AvailableView details
  3. List unique categoriesDISTINCT · LIMIT · Beginner · 15 min
    Access requiredView details
  4. Filter a price rangeBETWEEN · Beginner · 15 min
    Access requiredView details
  5. Filter multiple statusesIN · Beginner · 15 min
    Access requiredView details
  6. Search for a prefix with LIKELIKE · Beginner · 15 min
    Access requiredView details
  7. Identify missing deliveriesIS NULL · Beginner · 15 min
    Access requiredView details
2Module 2Prepare and summarise dataHandle NULL, text, dates, calculations and first indicators.0 / 8
  1. Replace a NULL value with COALESCENULL · COALESCE · Beginner · 15 min
    Access requiredView details
  2. Calculate a price including taxExpressions · ROUND · Beginner · 15 min
    Access requiredView details
  3. Assemble a product labelText · Concatenation · Beginner · 15 min
    Access requiredView details
  4. Normalize a list of citiesTRIM · UPPER · DISTINCT · Beginner · 15 min
    Access requiredView details
  5. Extract the year of registrationDates · EXTRACT · Beginner · 15 min
    Access requiredView details
  6. Calculate paid order indicatorsCOUNT · SUM · AVG · Beginner · 15 min
    Access requiredView details
  7. Group revenue by categoryGROUP BY · HAVING · Beginner · 15 min
    Access requiredView details
  8. Keep customers without ordersLEFT JOIN · COUNT · Beginner · 15 min
    Access requiredView details
3Module 3Join tables without breaking the grainChoose the right join and control what each row represents.0 / 7
  1. Connect customers and ordersINNER JOIN · Intermediate · 25 min
    Access requiredView details
  2. Find customers without ordersLEFT JOIN · HAVING · Intermediate · 25 min
    Access requiredView details
  3. Calculate the average basket per customerJOIN · AVG · Intermediate · 25 min
    Access requiredView details
  4. Calculate revenue using three tablesJOIN · GROUP BY · Intermediate · 25 min
    Access requiredView details
  5. Connect a table to itselfSELF JOIN · Intermediate · 25 min
    Access requiredView details
  6. Find the first orderMIN · GROUP BY · Intermediate · 25 min
    Access requiredView details
  7. Filter an average basket with HAVINGAVG · HAVING · Intermediate · 25 min
    Access requiredView details
4Module 4Subqueries and set operationsTest existence, compare a benchmark and combine sources.0 / 5
  1. Test for the existence of a large orderEXISTS · Intermediate · 25 min
    Access requiredView details
  2. Compare to average priceSubquery · AVG · Intermediate · 25 min
    Access requiredView details
  3. Merge customers and prospectsUNION · Intermediate · 25 min
    Access requiredView details
  4. Keep origin with UNION ALLUNION ALL · Intermediate · 25 min
    Access requiredView details
  5. Find the intersection of two listsINTERSECT · Intermediate · 25 min
    Access requiredView details
5Module 5Structure and control an analysisUse CTEs to reconcile, deduplicate and expose the method.0 / 7
  1. Segment customers with a CTECTE · CASE · Intermediate · 25 min
    Access requiredView details
  2. Detect duplicate emailsQuality · HAVING · Intermediate · 25 min
    Access requiredView details
  3. Reconcile orders and paymentsQuality · Subqueries · Intermediate · 25 min
    Access requiredView details
  4. Calculate the overall margin with a CTECTE · Calculations · Intermediate · 25 min
    Access requiredView details
  5. Rank the top three categoriesCTE · TOP N · Intermediate · 25 min
    Access requiredView details
  6. Compare each month to the previous oneCTE · Auto-join · Intermediate · 25 min
    Access requiredView details
  7. Measure phone completenessNULL · COUNT · Intermediate · 25 min
    Access requiredView details
6Module 6Build reliable KPIsTurn a business request into dated, segmented and interpretable indicators.0 / 6
  1. Calculate monthly revenueDates · GROUP BY · Intermediate · 25 min
    Access requiredView details
  2. Analyze a quarter with limitsDates · WHERE · Intermediate · 25 min
    Access requiredView details
  3. Classify inventory riskCASE WHEN · Intermediate · 25 min
    Access requiredView details
  4. Calculate multiple statuses in one lineCASE · Aggregations · Intermediate · 25 min
    Access requiredView details
  5. Calculate margin by categoryProject · joins · Intermediate · 25 min
    Access requiredView details
  6. Track monthly payment rateProject · KPI · Intermediate · 25 min
    Access requiredView details
7Module 7Cohorts, segmentation and time seriesMove into multi-step Analyst cases and advanced functions.0 / 5
  1. Avoid double counting after several joinslevel of detail · joins · Aggregations · Advanced · 55 min
    Access requiredView details
  2. Building a cohort and measuring retentionCohorts · Retention · Dates · Advanced · 55 min
    Access requiredView details
  3. Build a complete RFM segmentationRFM · Segmentation · CASE · Advanced · 55 min
    Access requiredView details
  4. Measure a funnel without counting duplicate eventsFunnel · Conversion · FILTER · Advanced · 55 min
    Access requiredView details
  5. Analyze a time series with missing monthsTime series · LAG · Frames · Advanced · 55 min
    Access requiredView details
8Module 8Audit and decide independentlyDetect grain bias, justify controls and defend a business conclusion.0 / 5
  1. Deduplicate with a deterministic ruleQuality · ROW_NUMBER · Ties · Advanced · 55 min
    Access requiredView details
  2. Analyze the margin and real contributionMargin · Contribution · Multi-table · Advanced · 55 min
    Access requiredView details
  3. Audit a KPI before publicationKPI quality · level of detail · Reconciliation · Advanced · 55 min
    Access requiredView details
  4. Clean an imperfect dataset before analysisQuality · NULL · References · Advanced · 55 min
    Access requiredView details
  5. Conduct an autonomous seller analysisAutonomous analysis · Decision · Advanced · 55 min
    Access requiredView details