Top SQL Interview Questions to Practice

6 minutes

With an average pay of around $112,120 per year and a healthy job outlook, database positions, particularly those involving SQL skills, are a hot commodity. But, with high competition comes high pressure to ace the interview. Responding to questions with tangible examples  and showing the best of your SQL abilities can give you a leg up on the competition.

A little prep can go a long way towards giving you the confidence you need to make the best possible impression during the interview process. Keep reading to learn the kinds of questions to expect during a SQL interview, how to answer them, and how our courses can help you prepare. Then, put your skills to the test in our updated Data Analyst and Data Scientist Interview Prep paths. You’ll answer open-ended questions on the spot and receive instant AI-generated feedback to help you identify and enhance areas of weakness.

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Behavioral SQL job interview questions

During the interview process, you’ll likely have two different interviews — a technical interview and a behavioral interview. For the behavioral interview, sometimes called “situational,” you’ll be asked questions that evaluate your soft skills, not your technical ones. Here are common behavioral interview questions to prepare for.

Adaptability and ability to learn

Questions related to adaptability and learning give you a chance to show your interviewer that you can adjust to difficult situations and grasp new skills and concepts. You can go into  as much detail as you’d like while answering these questions, but also keep in mind that direct, tangible examples from your past experience will help draw your audience in.

Describe a time when you had to learn a new programming language.

As you answer this question, try to showcase your ability to learn under pressure. If you’re new to coding, no problem. Discuss the reasons that drove you to learn and how you made sure you gained a working knowledge of the language.

Talk about a time when you had to incorporate feedback.

Being able to accept feedback while on a development team is sometimes more important than your coding knowledge. Before going into the interview, try to have at least one example in mind where you had to change what you did or alter your approach to a problem based on someone else’s ideas.

Communication skills

Have you ever had to incorporate input from upper management? These scenarios come up more often than you might think, and how you communicate and work with the management team to figure out a new solution is a great story to talk about during an interview.

This is your chance to show your interviewer that you know how to:

  • Listen carefully
  • Keep your eye on high-level objectives
  • Incorporate abstract ideas or desires into your coding
  • Produce products that serve the needs of both customers and the higher-ups

If you’re short on experiences like this, don’t worry. Even if all you had to do was speed up your process to meet a deadline, you can still share your experience, the challenges involved, and how you overcame them.

Describe a time when you disagreed with a team member.

Whether it was a difference of opinion regarding the business logic of code or how to present your final product, interactions like these can be powerful examples during your interview.

Not only can you use scenarios like these to explain how much you learned from a teammate, but you can also highlight how you communicated your opinions and advice during the situation as well. As you answer, be sure to acknowledge:

  • Something you learned from your team member
  • Something you learned from the experience, in general
  • A way in which your thinking shifted based on what you learned from the interaction

These details show you’re introspective and humble when interacting with team members.

Technical SQL interview questions

Once you complete the behavioral interview, you’ll move on to the technical interview. In some cases, you may get a heads up about what questions to expect during the technical interview and the project you’ll be asked to complete. But, not always.

Here are some of the kinds of questions you should get comfortable answering before the interview.

Explain some of the different kinds of SQL indexes.

To answer this question, you’ll want to specifically outline indexes such as:

  • Clustered index, which contains groups of data stored in the same area of a table so they can be retrieved together
  • Non-clustered index, which is used when you need key-based queries, instead of ranges, which work better with clustered indices

Keep in mind that the majority of SQL databases will make the best index decision for you — based on your use case. It may be helpful to mention this as well.

What’s the difference between a cross join and a natural join?

A cross join will result in the Cartesian product between a set of two tables. You use it when you’re trying to make a combination using all of the rows from two different tables.

A natural join produces a table that combines columns of the same type and name. The shared columns between two tables will be eligible for this kind of join.

Describe a situation where you would decide to use a blank space or a zero instead of a NULL value within a row.

This question tests your knowledge of the difference between NULL, blank, and zero, which all output “nothing” for the end-user. Here’s a way to answer it.

When someone is filling out a form, for instance, NULL can indicate that someone may be able to provide an answer in a field but they choose not to. Zero, on the other hand, means there was no answer to be given, so the user had no choice but to enter “nothing.”

How to practice for the technical interview

To prepare for an SQL job or any database-related interview, you can rely on our skill paths. In our recently updated interview prep courses, you’ll get to practice answering free-response questions and receive AI-generated feedback:

We also offer technical interview practice for:

So, whether you’ve just begun thinking about a career in SQL programming or already have the basic knowledge you need, you can use the tips above to impress whoever’s on the other side of the table. The courses, career paths, and skill paths we offer can put you in a position to confidently enter an interview ready to leave a great impression.

Remember to prepare ahead of time, throw in some fun practice sessions, and always use tangible examples to back up any claims you make about your skills or experience. To get you started on a new SQL journey, you can use Analyze Data with SQL, Analyze Business Data with SQL, Learn SQL, and How to Transform Tables with SQL.

This blog was originally published in October 2021 and has been updated to include details about our new AI interview prep features.

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