What Are Basic SQL Interview Questions?

It can be nerve-wracking to head into an interview - especially if you want to work in SQL. What kind of questions can you expect? What can you prepare for before an interview for an SQL position?

Here are a few common questions you can anticipate for an SQL interview:

• What is Database?
• What is SQL?
• What is the Difference Between DBMS and RDBMS?
• What Are the 5 Basic SQL Commands?
• Explain SQL Constraints
• What is a trigger?

These appear often in an interview for an SQL position.

Read on to learn more about the most common questions that appear in an interview! There’s a lot to consider to help you feel confident about your prospects in this technological world. Let’s get started!

What is Database?

First, a very basic question - what is a database? If you are going to work in a position that handles SQL, you need to know what a database is in your position. So, what is a database?

A database is:

• A collection of organized data
• Stored, then retrieved, in a digital manner
• Anything from simple to vast and complex

The database is the foundation for SQL, so you should be familiar with the term and its definition.

Databases are vital aspects of any organization. They make it possible to utilize various approaches when working with a standard query language.

What is SQL?

This question is just as critical as the first - what is SQL? If you don’t know what SQL is or how to recite it to an interviewer, you will have a more difficult time getting a recruiter to hand you a job in this field.

SQL is:

• Structured query language
• A way to access, manipulate databases
• A method of data management

Many companies take advantage of SQL for all of their activities.

You should know what SQL is if you’re headed into an SQL profession, and you should be ready to describe it to an employer in an interview. This basic question shows you’re knowledgeable about the field you’re headed into for their organization.

What is the Difference Between DBMS and RDBMS?

Another question that might appear is - what is the difference between DBMS and RDBMS? You should be able to tell the two apart and relay that information back to the professional that is interviewing you for the job.

Here’s the difference between the two:

• DBMS: A database management system, which helps maintain and build any databases.
• RDBMS: A relational database management system, which is based on the relational model of the DBMS.

They are not the same in the SQL world.

It’s vital to understand that these are both components of SQL, but they are not the same thing. You should know how to verbalize what they are and the differences between them before an interview.

What Are the 5 Basic SQL Commands?

Next - what are the five basic SQL commands? An interviewer may ask this question to monitor your knowledge of the fundamentals. You should know the five commands to help the recruiter feel confident in your ability.

Here are the five basic SQL commands you should know:

• ALTER
• UPDATE
• DELETE
• INSERT
• CREATE

These are a must when it comes to an SQL interview, basic commands all employees should be familiar with in SQL.

Of course, many more commands come with SQL. However, these are the fundamentals that pave the way for everything else. Ensure you know how to recite them before you head into your interview.

What is a Trigger?

Another question an interviewer might ask is - what is a trigger? You should be able to answer this with ease if an employer questions you.

A trigger is a stored program that happens automatically when INSERT, DELETE, or UPDATE commands happen. There are also other commands they respond to in an SQL system.

Triggers are a response to a command in the system. Ensure you are prepared to talk about triggers before you head to your interview for the best results!

Explain SQL Constraints

When working with SQL, you will handle constraints every single day in your place of work. Constraints are the items that dictate the rules in a table of data. Constraints in SQL work to state what can and cannot be done. Again, this question is a foundational one that all individuals working in SQL should know without a doubt.

Here are the most common SQL constraints that exist:

• NOT NULL: Stops NULL from going into a column
• CHECK: Checks that every number satisfies a condition
• DEFAULT: Assigns a default value if nothing has been placed in that particular area
• UNIQUE: Puts unique numbers into the field
• INDEX: Creates a faster retrieval of records
• PRIMARY KEY: Identifies each record in the table in a unique manner
• FOREIGN KEY: Made referential integrity for moving purposes

These are the most common constraints utilized in the SQL world.

When making a table, you can specify constraints for the best results. Ensure you know what each one is for the best possible interview. A knowledge of these basic materials will be wildy helpful in the future as you take steps to get closer to a career in the SQL field.

Conclusion

If you are headed into an interview for an SQL position, it can feel like the world is falling apart. With knowledge of some of the most basic SQL interview questions, you can approach your interview with the confidence that you will know at least one answer. These are a few of the foundational questions that appear most often.

We hope this information was helpful! It can be scary to interview for a new job, but knowing what to expect in the interview is one of the best ways to prepare yourself for speaking to the hiring manager. You already know this information - now, all you have to do is figure out how to verbalize it to an interviewer. Take it one step at a time for the best results.