Top 10 SQL Interview Questions and Answers

sql interview questions

Structured Query Language (SQL) is a programming language that’s used to manipulate and communicate with databases. SQL programs are put into place by organizations as a way to better access the information and data stored in their databases.

With more companies relying on big data analytics than ever before, employees with strong SQL skills are highly sought after. SQL is used in many different jobs such as business analysts, software engineer, systems administratorsdata scientists, and many more. To help you with your job search, we’ve put together the top ten SQL interview questions you might encounter as well as some sample answers to give you a leg up on your competition.

Table of Contents:

  1. Tell me a little about yourself.
  2. What are your weaknesses?
  3. Do you work better on a team, with just one partner, or alone?
  4. Where do you see yourself in five years?
  5. Why should we hire you?
  6. What are the standard SQL commands every SQL developer should know?
  7. What is a Relational Database Management System (RDBMS), and which one are you most familiar with?
  8. What is a view and what are some advantages of it?.
  9. Provide a sample of a correlated subquery.
  10. Name some commands that can be used to manipulate text in T-SQL code and explain what they do.

1. Tell me a little about yourself.

This question is almost always included in interviews, and while it may seem simple on the surface, it’s actually one of the most difficult questions to answer because it’s so general. Remember to keep your answer concise and relevant to the potential role, including beneficial education and work experience. A solid answer could be something like:

“I have a degree in computer science and have been using this for the past three years as a backend developer at my current company. I find that I typically take an analytical approach when faced with problems, and I think through a variety of solutions before I begin trying them out. I have experience working in fast-paced environments, and am comfortable working both independently and as part of a team.”

2. What are your weaknesses?

One of the biggest mistakes you can make with this question is to say you have no weaknesses, as it will make you appear either arrogant or like a robot. Instead, use this question as a chance to identify a true weakness that you would like to improve upon. Employers are much more likely to respond well to authenticity versus perfectionism. Read specific examples of how to answer the “what are your weaknesses” question here.

Be prepared with:

“One of my biggest weaknesses is that I don’t have a lot of relevant work experience because I recently graduated. However, I think this is also an advantage as I’m coming to the workforce with a fresh perspective and am educated with the latest programming methods and strategies. I also have struggled with being a little disorganized in the past, but I’ve found a great app that helps me stay on track with projects and deadlines.”

3. Do you work better on a team, with just one partner, or alone?

With this behavioral interview question, interviewers are aiming to assess your personality as well as your preferred methods for completing tasks. Even if you lean more toward one way than the other, it’s important to demonstrate that you’re motivated enough to work alone yet are a good team player and able to collaborate.

A sample answer could be:

“I’d have to say that I’m equally comfortable working independently or as a member of a team. I’m a self-starter who can maintain an efficient pace to complete projects on my own, but I also enjoy collaborating with and learning from others on a team.”

4. Where do you see yourself in five years?

For this common question, the hiring manager is usually looking for a response that shows you have goals in mind for the future and that you’re ambitious. You’ll want to be realistic, but keep your plan in context with what makes sense for your potential role in the company. We also have a separate article that helps answer the “Where do you see yourself in five years“. Try an answer like:

“I was originally drawn to this position as I can definitely see myself as someone with deep SQL expertise in the next five years. I would hope that I’d be more of a senior engineer by that point and able to take on more leadership roles within projects. I’m also interested in the idea of potentially taking on more of a management role in order to help new hires gain a further understanding of development.”

5. Why should we hire you?

Your answer to this question is an opportunity for you to not only sell yourself to the interviewer, but also a chance for you to set yourself apart from the competition. Be specific in your answer and concisely summarize your relevant strengths, experience, qualifications, and achievements:

“I know that I’d be an asset in this position as I’ve already proven my skills in previous internships at high-profile companies and have a portfolio of successful projects. I started programming at a young age, and I regularly contribute to open-source coding projects, which proves my ambition and overall passion for what I do. I have the knowledge to start positively contributing on my first day, and I know that I could bring a new and unique perspective to the company.”

6. What are the standard SQL commands every SQL developer should know?

Your interviewer will likely want to check your knowledge to see if you can name the most essential commands necessary for programmers.
Your answer might include commands like:

“Some of the standard commands every SQL developer should know include:

  • SELECT – which allows you to select data from a database
  • WHERE – which allows you to apply specific criteria to what you select
  • ORDER – which is used to sort the results
  • JOIN – which is used to join the related data that’s stored in one or more tables
  • UNION – which allows you to append rows to each other”

7. What is a Relational Database Management System (RDBMS), and which one are you most familiar with?

Having knowledge of an RDBMS is necessary as it’s an important component of what you’ll be building and organizing with SQL, and relational databases are essentially the warehouse for your data. Employers will want to ensure they’re hiring an SQL developer who’s experienced with the particular set of web technologies that they use within their company, which is why it’s beneficial for you to have experience with multiple RDBMSs.

You could show your experience with:

“An RDBMS is a system that organizes data into tables, which are further organized into columns and rows. This relational model is an ideal way to sort through large volumes of data, as it can be queried in an almost unlimited number of ways. I have the most experience with PS/SQL, but I’m also familiar with T-SQL and JET SQL.”

8. What is a view and what are some advantages of it?

In our world of ultimate connectivity, views are vital as they’re used to implement the security mechanism in the SQL server. The hiring manager will want to assess your knowledge of this statement while also checking to see if you understand when you would use a view over a regular table. You might answer:

“A view is a virtual table that contains rows and columns similar to a real table, yet does not contain data of its own. Some advantages of views are that they take up no space, they can be used to restrict access to the database, and they offer a simple way to retrieve complicated query results that need to be executed frequently.”

9. Provide a sample of a correlated subquery.

As with any interview for a job in which you’ll be writing specific programming languages, you can bet that you’ll have multiple questions that require you to show your skills firsthand. Interviewers will want to see your coding abilities as well as test your general adaptability.

You could provide something like:

SELECT employee_number, name
FROM employees AS emp
WHERE salary > (
SELECT AVG(salary)
FROM employees
WHERE department =

10. Name some commands that can be used to manipulate text in T-SQL code and explain what they do.

This is where having experience with multiple SQL extensions will be handy as interviewers are more than likely to assess how versatile your programming knowledge is in regard to SQL. T-SQL (Transact-SQL) is an extension that adds further features to the language. Some potential commands could be:

  • REVERSE( character_expression )
    • Returns the reverse of a character expression
  • REPLICATE( character_expression, integer_expression )
    • Repeats a character expression for a specified number of times
  • CHARINDEX( findTextData, textData )
    • Returns the starting position of the specified expression in a character string
  • LOWER ( character_expression )
    • Returns a character expression after converting uppercase character data to lowercase
  • LEFT( character_expression, integer_expression )
    • Returns the left part of a character string with the specified number of characters

While these top ten SQL interview questions only begin to help you prepare, they’ll give you an idea of what to expect when it comes to both general as well as SQL-specific questions. By carefully researching the job position, the company, and practicing sample SQL interview questions and answers such as those above, you’ll be one step closer to obtaining the programmer role you’ve always wanted.

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