No matter if you are a fresher or an experienced candidate, SQL is a very basic topic. Especially if you are a backend or full-stack developer, it is very common that interviewees will ask you questions on SQL.

SQL Query Interview Questions

Here are some of the very basic SQL interview questions that will help you to prepare and crack the interview. Check this list right now.

1. How to find duplicate records in the table?
2. How to delete duplicate rows from a table?
3. What is the difference between union and union all?
4. What is the difference between rank, row_number, and dense_rank?
5. Write a query to find records in a table that are not present in another table?
6. Find the second highest salary employees in each department.
   (This question has been asked in many interviews.)
7. Find employees with salaries more than their manager’s salary.
8. What are the different types of SQL join?
9. Difference between inner and left join. (You can find the answer to this question in the above link.)
10. Write a SQL query to update a table and swap gender values.
11. Find the number of records in the output after performing different kinds of join.
    Hint: To answer this question, you should know the different kinds of SQL-join operations.

To answer all these above questions, you should have very good commands over SQL basic concepts.

In the above list, the interviewer is asking you to write a SQL command. The interviewer can also ask theoretical questions as well.

12. What is the difference between SQL and NoSQL?

Not necessary you will be asked for the exact questions in the interview. But knowing answers to these questions will help you to clear your concept. Once you have command over these concepts, you can ask any flavor of questions.

This is all about some of the basic and common SQL query interview questions.

In case of any doubt, write me in a comment. If you come across any other SQL questions in the interview, do share them with us.

All the best!