2023: 11 Stored Procedure Interview Questions with Answers"

Updated 11 October 2023

A stored procedure is a prepared, structured query language (SQL) code that you can save and use repeatedly. Stored procedure interview questions aim to understand a candidate's technical knowledge of programming-language concepts. It is essential for a candidate to highlight their familiarity with the functions, uses and benefits of various programming languages for a stored procedure interview. In this article, we look at some stored procedure interview questions that hiring managers ask and provide sample answers that you can review to help prepare for your next interview.

11 Stored Procedure Interview Questions And Answers

The following are some stored procedure interview questions that recruiters may ask during technical interviews:

1. What do you know about stored procedures?

Interviewers could ask this question at the beginning of your interview to gauge your basic understanding of stored procedures. You can provide a simple, cohesive answer that demonstrates your knowledge of and experience with the concept instead of a bland, textbook definition. If you can, use an example to demonstrate your use of the concept.

Example: ‘Stored procedure is a named group of structured query language (SQL) statements that an individual or organisation stores in a server database or database management system (DBMS). The stored procedure can accept input and output parameters to provide several clients with access to a single stored procedure over a network using different input data. It reduces a network's traffic and increases its performance. Once the procedure receives any modifications, every client using the stored procedure gets access to the updated version.'

2. What are the different uses of stored procedures?

An interviewer may ask this question to determine if you know where to apply stored procedures. You can mention company-specific use cases and applications in your answer. You can also describe the features and benefits of stored procedures.

Example: "I typically use stored procedures for data validation and as an access-control mechanism. This application uses a centralised, self-contained logic. I could also use a stored procedure for complex procedures that require the processing of massive amounts of data. I could also use it to establish logic implementation access for data to enable faster execution and reduce network traffic."

3. What types of stored procedures are in an SQL server?

Interviewers commonly ask this question to test your comprehension of the differences between the various types of stored procedures. You can demonstrate your understanding by listing the principal features of each type. Providing a brief explanation of each procedure can demonstrate your understanding of the concept to a potential employer.

Example: ‘There are two types of stored procedures in SQL servers. The first is the system-defined stored procedure you can use to perform administrative activities in the SQL server. The second type is the user-defined stored procedure, a module that encapsulates the code for reuse. You can further segment user-defined stored procedures into two types, transact SQLs and CLR stored procedures.'

4. What are the advantages of stored procedures?

Since stored procedures are easy to use, they have a variety of advantages. Briefly elaborate on each key benefit. This can ensure the interviewer that you are aware of the process's benefits and able to leverage them in your work.

Example: 'One of the primary advantages of a stored procedure is that it immediately processes information on the database server, reducing network usage across servers. It allows the database administrator to control access, improving its security. Stored procedures reduce development costs, increase reliability and enhance database performance. They can encapsulate logic. This allows you to change the code without affecting client data by reducing the chances of faulty client programs corrupting data. Stored procedures also allow you to securely access other database objects and can prevent SQL injection attacks.'

5. What are the disadvantages of stored procedures?

Every process can have areas of opportunity or disadvantages. Interviewers may ask this question to test your awareness of the system's shortcomings. You can list and elaborate on the disadvantages of stored procedures from your experience.

Example: 'Stored procedures do have a few disadvantages. One is that writing and maintaining stored procedures requires specialised skills. Technicians couple stored procedures with the database system in a way that makes debuggers potentially unavailable. The language can differ from one database system to another, and it can sometimes be hard to understand the logic in dynamic SQL. Additionally, the exception handling in stored procedures may be incorrect and prevent you from using certain objects.'

6. What is a return statement?

Return statements control flow blocks in stored procedures. They can set the return code value to check for possible errors. Explain the basic concept of a return statement and its functions in your answer.

Example: ‘A return statement terminates the execution of a particular stored function. It returns the control flow to the stored procedure's caller and ends the SQL procedure immediately. In a stored function, it is essential to have at least a single return statement. For multiple functions, you can create multiple exit points.'

7. What are the benefits of running a stored procedure on a database engine?

Stored procedures offer numerous advantages, such as improved performance, higher productivity, ease of use and increased scalability. You can highlight some specific benefits while answering this question. You can also share some of your previous experiences using stored procedures.

Example: 'For industries where automation is key, organisations can select the database for running stored procedures. You can avoid network communication since it runs on a specialised database server. You can also use it for the execution of complex SQL statements.'

8. When would you use stored procedures or functions?

Stored procedures and functions are different concepts. To answer this question, you can briefly explain the difference between stored procedures and functions. You can also mention their applications to show a more in-depth knowledge.

Example: 'Since functions are computed values, they cannot perform permanent environmental changes to the SQL server. You cannot insert them in the statement or update them. If a function returns a scalar value, or you can combine it with another after it returns a scalar set, you can use it in line with the SQL statements. You can utilise these statements when the application has a centralised applied logic. Stored procedures help validate data and complex processes.'

9. How would you practise your stored procedure skills?

Interviewers may ask this question to assess your way of improving your SQL skills. You can explain a few of the practices you follow to enhance your stored procedure skills. You can also describe how these skills can help juniors or trainees in the department.

Example: "I feel that it is important to start practising SQL skills at the very beginning of your career and throughout. It is helpful to write daily SQL queries and document any learnings. You can also track any reported errors that could be useful for conducting training sessions on SQL."

10. What are extended procedures, and when would you use them?

Extended procedures are DLL-based programs that perform tasks like stored procedures. You typically write them in a standard programming language and utilise the OpenData API of an SQL server to set parameters and provide results. They run in the SQL server's process space, and you can access them from the master database.

Example: 'Extended procedures, or external procedures, allow you to create external routes in your preferred programming language. Extended stored procedures run directly in the address space of a SQL server. To program them, you use the SQL server's extended stored procedure API.'

11. Explain the difference between stored procedures and triggers.

Users can explicitly invoke stored procedures. They can input data as a parameter before returning values. A trigger is a stored procedure that automatically runs when events occur.

Example: ‘The main difference between stored procedures and triggers is that triggers run automatically, whereas stored procedures run manually. It is essential that you identify an event or action while creating a trigger. In contrast, identification is not very important for creating a stored procedure. You can call a stored procedure in a trigger, but you cannot call a trigger in a stored procedure. Triggers execute implicitly, and stored procedures execute explicitly.'

Tips To Prepare For Stored Procedure Interview Questions

The following tips can help you create a positive impression during your interview:

Do your research. Study the role and the company. Visit the company website or social media platforms to help you anticipate what industry-related questions the recruiter may ask you during the interview.
Check your skill proficiency. Ensure that you meet the skill requirements the company outlined for the position. Check that you understand the preferred programming languages and have the required years of programming experience and skills.
Compile a list of stored procedure interview questions. You can ask a family member or a friend to help you prepare for the interview by having them ask you questions from your list. Practising your answers can help you improve your delivery and body language and be ready to confidently answer any queries the interviewer asks.