SQL Developer interview questions & mock practice
A SQL Developer interview in 2026 runs across 4 rounds — core sql round, procedures & t-sql/pl-sql, optimisation round, design & scenario. Below are the most-asked SQL Developer interview questions and a focused prep plan. Rehearse every answer with OnJob's free AI mock interview and get instant, specific feedback before the real one.
The SQL Developer interview process
Advanced SQL, stored procedures, query tuning and database design — the SQL-developer interview for backend, BI and database teams.
Core SQL round
Joins, aggregations, subqueries and window functions.
Procedures & T-SQL/PL-SQL
Stored procedures, functions, triggers and cursors.
Optimisation round
Indexing, execution plans and query tuning.
Design & scenario
Schema design, normalisation and a practical query problem.
Most-asked SQL Developer interview questions
12 of the questions SQL Developer candidates are asked most often in India. Practise answering each one out loud in your AI mock interview.
- 1. What is the difference between INNER, LEFT, RIGHT and FULL OUTER JOIN?
- 2. Write a query to find the second-highest salary in a table.
- 3. What is the difference between WHERE and HAVING?
- 4. Explain window functions like ROW_NUMBER(), RANK() and DENSE_RANK().
- 5. What is the difference between a stored procedure and a function?
- 6. What is database indexing, and what is the difference between clustered and non-clustered indexes?
- 7. Explain the difference between DELETE, TRUNCATE and DROP.
- 8. What is a CTE, and how does a recursive CTE work?
- 9. What are the ACID properties, and what are transaction isolation levels?
- 10. How do you find and remove duplicate rows in a table?
- 11. What is the difference between UNION and UNION ALL?
- 12. How would you optimise a slow-running query?
How to prepare for your SQL Developer interview
Be fluent in joins, GROUP BY, subqueries, CTEs and window functions — write them quickly and correctly.
Know the difference between DELETE/TRUNCATE/DROP, clustered vs non-clustered indexes, and UNION vs UNION ALL.
Practice writing stored procedures, functions and triggers in your dialect (T-SQL or PL/SQL).
Understand query optimisation: how indexes work, reading execution plans and avoiding table scans.
Be ready to design a normalised schema and write tricky queries (Nth highest, duplicates, running totals) under time pressure.
Practise other roles
- Software Engineer
- Frontend Developer
- Backend Developer
- Full Stack Developer
- Data Analyst
- Data Scientist
- Product Manager
- DevOps Engineer
- Java Developer
- Python Developer
- UI/UX Designer
- Sales / Business Development
- Digital Marketing
- HR / Recruiter
- Accountant
- Customer Support
- Data Engineer
- Machine Learning Engineer
- QA / Test Engineer
- Android Developer
- iOS Developer
- Business Analyst
- Project Manager
- Scrum Master
- React Developer
- Node.js Developer
- Cloud Engineer (AWS)
- Cybersecurity Analyst
- Network Engineer
- Database Administrator
- SEO Specialist
- Content Writer
- Graphic Designer
- Sales Executive
- Business Development Manager
- Operations Manager
- Financial Analyst
- Chartered Accountant
- Customer Success Manager
- Technical Support Engineer
- Civil Engineer
Interview prep guides
SQL Developer interview — FAQs
What questions are asked in a SQL Developer interview?
Common SQL Developer interview questions include: What is the difference between INNER, LEFT, RIGHT and FULL OUTER JOIN? Write a query to find the second-highest salary in a table. What is the difference between WHERE and HAVING? Explain window functions like ROW_NUMBER(), RANK() and DENSE_RANK(). Interviews usually run across 4 rounds — Core SQL round, Procedures & T-SQL/PL-SQL, Optimisation round, Design & scenario. Practice all of them with instant AI feedback using OnJob's free mock interview.
How many rounds are in a SQL Developer interview?
A typical SQL Developer interview has 4 rounds: Core SQL round (Joins, aggregations, subqueries and window functions.); Procedures & T-SQL/PL-SQL (Stored procedures, functions, triggers and cursors.); Optimisation round (Indexing, execution plans and query tuning.); Design & scenario (Schema design, normalisation and a practical query problem.).
How do I prepare for a SQL Developer interview?
To prepare for a SQL Developer interview: Be fluent in joins, GROUP BY, subqueries, CTEs and window functions — write them quickly and correctly. Know the difference between DELETE/TRUNCATE/DROP, clustered vs non-clustered indexes, and UNION vs UNION ALL. Practice writing stored procedures, functions and triggers in your dialect (T-SQL or PL/SQL). Then run a full AI mock interview on OnJob to rehearse out loud and get instant, specific feedback before the real thing.
What skills do I need for a SQL Developer role?
Core SQL Developer skills tested in interviews include SQL, Stored Procedures, Query Optimisation, Indexing, PL/SQL, Database Design, Triggers. OnJob shows you exactly which of these skills stand between you and a 100% match on every live SQL Developer job.
Is OnJob's SQL Developer mock interview free?
Yes. OnJob's AI mock interview is free to start (₹0) and gives you instant feedback on your answers. Pro (₹99/month) adds unlimited interview-prep AI alongside recruiter tracking and unlimited applications.
Ace your SQL Developer interview
Rehearse every SQL Developer question out loud with OnJob's AI mock interview and get instant, specific feedback. Then apply to AI-matched jobs in one click — free to start.
Everything about SQL Developer on OnJob
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