Dataford
Dataford
Top 50
Topic roadmap
Updated weekly · Last refresh Nov 3

Top 50 sql Interview Questions

The most frequently asked sql questions across all roles and companies, ranked by real interview frequency. Updated daily.

50questions
~17htotal time
589companies covered
Track your progressSign up free to work through all 50 questions and resume where you left off.
Start practicing free →
1
SQL & Data ManipulationStart here. 48 questions · ~970 min
SQL Query OptimizationMedium
Practice
Recently asked

Optimize a slow PostgreSQL query that aggregates completed transactions while preserving customers with no matching activity.

Performance Tuningdatabase optimizationindexesDDroisysCapgeminiNomura
SQL Window Functions Moving AverageMedium
Practice
Recently asked

Calculate a three-day moving average of active-client revenue using aggregation and SQL window functions.

Window FunctionsData AnalysissqlEEvalueserveSShyena Tech YarnsAATB Financial
SQL Query PracticeEasy
Practice
Recently asked

Return the second-highest distinct non-null salary from a single employee table.

null handlingsqldatabase queryingBBureau VeritasPayUItc Infotech
SQL Window Functions Rolling AverageMedium
Practice
Recently asked

Calculate three-day rolling average sales by region using aggregation, joins, and PostgreSQL window functions.

Window FunctionssqlAAreteSSweetwaterRRichemont
SQL Window Functions ExperienceMedium
Practice
Recently asked

Use SQL window functions to rank regions by average 2024 yield within each country.

Window FunctionsJoinsData ManipulationErnst & YoungKBRMaximus Tech
Truncate vs DeleteMedium
Practice
Recently asked

Explain how TRUNCATE and DELETE differ in row removal, transaction behavior, and identity handling.

database managementData Manipulationdata managementCCitiusTechSStandards AustraliaArcesium
Second and Nth Highest ValuesMedium
Practice
Recently asked

Find the second highest distinct salary and adapt the query to retrieve any requested salary rank.

Data Manipulationsqldatabase queryingTech MahindraSnowflake ComputingKKGISL
Optimizing Poorly Performing SQLHard
Practice
Recently asked

Optimize a PostgreSQL reporting query by reducing scanned rows, preserving unmatched records, and selecting the latest related review efficiently.

database optimizationlarge datasetsperformanceTata Consultancy Services (North America)PPriority Technology Holdings, LLCZillow
More SQL & Data Manipulation questions with a free account

Sign up to see every question

Create a free account to unlock this list and practice real interview questions.

Get my prep plan
2
More topics2 questions · ~40 min
More questions with a free account
The finish line: interview-readyComplete all 50 questions to finish this plan.