SQL stands for structured query language and is amongst the most in-demand skills for all jobs today that require the need to work around data and databases. There is a great demand in the market for professionals who have mastered SQL. Recruiters are always on the lookout for such resources. 

Whether you’re looking for a role as a data analyst, data scientist, data engineering, data administrator, or a web developer you must have a clear understanding about all the concepts of SQL.  If you want to crack an SQL job interview, you have to prepare yourself with the SQL questions that are often asked to test your technical skills.  Here is the list of 10 toughest SQL job interview questions.

1. How to enhance the speed of a stored procedure?

2. How to remove duplicate rows from the table?

3. What is ACID property in a database?

4. How do you check whether the date passed to Query is the date of given format or not? Write an SQL Query to show.

5. If you are a SQL Developer, how can you delete duplicate records in a table with no primary key?

6. Write SQL Query to fetch employee names having a salary greater than or equal to 5000 and less than or equal 10000?

7. Can you tell the sixth normal form in SQL server?

8. Can you tell in which files does SQL server actually store data?

9. How to find the maximum salary in each department of an organisation? Write an SQL Query to show.

10. Tell the major difference between the RANK() and DENSE_RANK() functions? Give an example.