Interactive SQL exercises
Solved SQL exercises: practise from beginner to advanced
Practise SQL online through progressive business cases. Each exercise provides fictional data, hints, result validation and an explained solution.
62 exercises shown
SELECTNo account
Select the correct columns
Show only the name and price of each product.
Level : BeginnerOpen exerciseWHERE · ORDER BYNo account
Filter and sort orders
Find orders over €50, from highest to lowest.
Level : BeginnerOpen exerciseINNER JOINSQL Essentials
Connect customers and orders
Associate each order with the name of the customer who placed it.
Level : IntermediateCompare plansDISTINCT · LIMITDiscovery
List unique categories
Display the first three unique categories in alphabetical order.
Level : BeginnerCreate a free accountNULL · COALESCEDiscovery
Replace a NULL value with COALESCE
Display clear labeling when a customer’s phone is absent.
Level : BeginnerCreate a free accountCOUNT · SUM · AVGSQL Essentials
Calculate paid order indicators
Calculate the volume, total and average over a specific area.
Level : BeginnerCompare plansGROUP BY · HAVINGSQL Essentials
Group revenue by category
Calculate totals by category and keep only the most important ones.
Level : BeginnerCompare plansLEFT JOIN · COUNTSQL Essentials
Keep customers without orders
Count the orders of each customer without excluding new registrants.
Level : BeginnerCompare plansCTE · CASESQL Essentials
Segment customers with a CTE
Calculate the total per customer, then transform this result into a business segment.
Level : IntermediateCompare plansBETWEENDiscovery
Filter a price range
Select an inclusive interval and check its limits.
Level : BeginnerCreate a free accountINDiscovery
Filter multiple statuses
Replace multiple OR with a readable business list.
Level : BeginnerCreate a free accountLIKEDiscovery
Search for a prefix with LIKE
Use a simple text pattern without confusing prefix and content.
Level : BeginnerCreate a free accountIS NULLDiscovery
Identify missing deliveries
Distinguish a missing date from an empty string or status.
Level : BeginnerCreate a free accountExpressions · ROUNDDiscovery
Calculate a price including tax
Transform a source price with a precise formula and alias.
Level : BeginnerCreate a free accountText · ConcatenationDiscovery
Assemble a product label
Create a readable label from two columns.
Level : BeginnerCreate a free accountTRIM · UPPER · DISTINCTDiscovery
Normalize a list of cities
Create a clean dimension before counting customers.
Level : BeginnerCreate a free accountDates · EXTRACTSQL Essentials
Extract the year of registration
Derive a calendar component without transforming the scope.
Level : BeginnerCompare plansDates · GROUP BYSQL Essentials
Calculate monthly revenue
Group together several channels over the same monthly period.
Level : IntermediateCompare plansDates · WHERESQL Essentials
Analyze a quarter with limits
Filter a complete period with an exclusive upper bound.
Level : IntermediateCompare plansLEFT JOIN · HAVINGSQL Essentials
Find customers without orders
Keep the starting population and isolate the absence of activity.
Level : IntermediateCompare plansEXISTSSQL Essentials
Test for the existence of a large order
Filter a population without duplicating it by its history.
Level : IntermediateCompare plansJOIN · AVGSQL Essentials
Calculate the average basket per customer
Only aggregate orders that are actually paid.
Level : IntermediateCompare plansSubquery · AVGSQL Essentials
Compare to average price
Use an aggregated value as a dynamic threshold.
Level : IntermediateCompare plansUNIONSQL Essentials
Merge customers and prospects
Create a single list from two compatible sources.
Level : IntermediateCompare plansTraining scenariosThese contextual repetitions reinforce an existing method. They preserve every historical link without pretending to be new canonical problems.Browse 118 scenarios
118 exercises shown
WHERE · ORDER BYSQL Essentials
Isolate actually paid transactions — an energy supplier · training scenario
Isolate actually paid operations in the context of an energy supplier, with a controllable result. You must produce the result, check it on the source data and explain what it allows you to decide in this energy supplier.
Level : BeginnerCompare plansGROUP BY · SUMSQL Essentials
Compare value per city — one energy supplier · training scenario
Compare the value per city in the context of an energy supplier, with a controllable result. You must produce the result, check it on the source data and explain what it allows you to decide in this energy supplier.
Level : BeginnerCompare plansCASESQL Essentials
Prioritize amounts — an energy supplier · training scenario
Prioritize amounts in the context of an energy supplier, with a controllable outcome. You must produce the result, check it on the source data and explain what it allows you to decide in this energy supplier.
Level : BeginnerCompare plansCOUNT · GROUP BYSQL Essentials
Count volume by status — an energy supplier · training scenario
Count volume by status in the context of an energy supplier, with a controllable result. You must produce the result, check it on the source data and explain what it allows you to decide in this energy supplier.
Level : BeginnerCompare plansDISTINCTSQL Essentials
List active categories — an energy supplier · training scenario
List active categories in the context of an energy supplier, with a controllable result. You must produce the result, check it on the source data and explain what it allows you to decide in this energy supplier.
Level : BeginnerCompare plansDATE_TRUNC · SUMSQL Essentials
Monitor monthly progress — an energy supplier · training scenario
Monitor monthly developments in the context of an energy supplier, with a controllable result. You must produce the result, check it on the source data and explain what it allows you to decide in this energy supplier.
Level : BeginnerCompare plansWHERE · ORDER BYSQL Essentials
Isolate actually paid transactions — a tourism agency · training scenario
Isolate the operations actually paid in the context of a tourism agency, with a controllable result. You must produce the result, check it on the source data and explain what it allows to decide in this tourism agency.
Level : BeginnerCompare plansGROUP BY · SUMSQL Essentials
Compare value by city — a tourism agency · training scenario
Compare the value per city in the context of a tourism agency, with a controllable result. You must produce the result, check it on the source data and explain what it allows to decide in this tourism agency.
Level : BeginnerCompare plansCASESQL Essentials
Prioritize amounts — a tourism agency · training scenario
Prioritize amounts in the context of a tourism agency, with a controllable result. You must produce the result, check it on the source data and explain what it allows to decide in this tourism agency.
Level : BeginnerCompare plansCOUNT · GROUP BYSQL Essentials
Count volume by status — a tourism agency · training scenario
Count volume by status in the context of a tourism agency, with a controllable result. You must produce the result, check it on the source data and explain what it allows to decide in this tourism agency.
Level : BeginnerCompare plansDISTINCTSQL Essentials
List active categories — a tourism agency · training scenario
List active categories in the context of a tourism agency, with a controllable result. You must produce the result, check it on the source data and explain what it allows to decide in this tourism agency.
Level : BeginnerCompare plansDATE_TRUNC · SUMSQL Essentials
Monitor monthly progress — a tourism agency · training scenario
Monitor monthly developments in the context of a tourism agency, with a controllable result. You must produce the result, check it on the source data and explain what it allows to decide in this tourism agency.
Level : BeginnerCompare plansROW_NUMBER · PARTITION BYSQL Analyst
Rank results in each region — software subscriptions training scenario
Rank results in each region using a software subscription dataset designed to control level of detail and variance. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : IntermediateCompare plansLAGSQL Analyst
Compare each month to the previous one — software subscriptions · training scenario
Compare each month to the previous one using a software subscription dataset designed to monitor level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : IntermediateCompare plansSUM OVERSQL Analyst
Building a monthly rollup — software subscriptions · training scenario
Construct a monthly total from a software subscription dataset designed to control the level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : IntermediateCompare plansAVG OVER · ROWSSQL Analyst
Smoothing a two-month trend — software subscriptions · training scenario
Smooth a two-month trend from a software subscription dataset designed to control the level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : AdvancedCompare plansFILTERSQL Analyst
Produce conditional KPIs by region — software subscriptions · training scenario
Produce conditional KPIs by region from a software subscription dataset designed to monitor level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : IntermediateCompare plansWindow · PercentageSQL Analyst
Measure the contribution of each line — software subscriptions · training scenario
Measure the contribution of each line from a software subscription dataset designed to monitor level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : AdvancedCompare plansCTE · ROW_NUMBERSQL Analyst
Keep top two lines per region — software subscriptions training scenario
Maintain the top two rows per region from a software subscription dataset designed to control level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : AdvancedCompare plansNTILESQL Analyst
Divide results into quartiles — software subscriptions · training scenario
Divide results into quartiles from a software subscription dataset designed to control level of detail and variance. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : AdvancedCompare plansAVG OVERSQL Analyst
Compare each value to its regional average — software subscriptions · training scenario
Compare each value to its regional average using a software subscription dataset designed to control the level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : IntermediateCompare plansQuality · HAVINGSQL Analyst
Detect duplicate business references — software subscriptions training scenario
Detect duplicate business references from a software subscription dataset designed to control level of detail and discrepancies. You must produce the result, check it on the source data and explain what it allows you to decide in this software subscription.
Level : IntermediateCompare plansROW_NUMBER · PARTITION BYSQL Analyst
Rank results in each region — national expeditions training scenario
Rank results in each region using a national shipment dataset designed to control level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this national expeditions.
Level : IntermediateCompare plansLAGSQL Analyst
Compare each month to the previous one — national expeditions · training scenario
Compare each month to the previous one using a national shipment dataset designed to control level of detail and variances. You must produce the result, check it on the source data and explain what it allows you to decide in this national expeditions.
Level : IntermediateCompare plansTwo focused paths reuse these experiences.
Progress remains shared: no content is duplicated.
3 exercises are available without an account, followed by 12 more in the free Discovery space. The catalogue contains a total of 62 canonical experiences. Run a first query.