20 Most Essential SQL Query Interview Questions & Answers

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SQL, or Structured Query Language, is the go-to programming language for managing and interacting with relational databases. It’s widely recognized across various fields, including data analytics, software development, and business operations, as a powerful tool for communicating with databases and extracting valuable insights from data.

Mastering SQL goes beyond just understanding its syntax—it’s about applying it in real-world situations. During the interview practical experience with SQL can showcase your ability to handle data efficiently. Whether you’re analyzing trends, optimizing queries, or managing databases, SQL proficiency can make you stand out in numerous tech-related roles.

When preparing for SQL interviews, expect to encounter questions that test not only your theoretical knowledge but also your problem-solving abilities in practical scenarios. To prepare for that we have created a list of the most asked SQL queries interview questions with practical examples that you can practice and gain deeper insight.

Advantages of SQL Queries Interview Questions

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20 most asked SQL Queries Interview Questions

To start with SQL queries interview questions, We’ve designed three sample tables: the Student Table, Program Table, and Scholarship Table. These tables will serve as the foundation for demonstrating a variety of query operations.

Student Table

STUDENT_IDFIRST_NAMELAST_NAMEGPAENROLLMENT_DATEMAJOR
301Aarav Mehta8.92024-01-15 9:00:00Data Science
302DiyaKapoor8.752024-01-15 8:45:00Mathematics
303SiddharthJoshi7.2024-01-15 10:15:00Biology
304PriyaVerma9.452024-01-15 11:00:00Chemistry
305 Aarohi Sharma8.52024-01-15 9:30:00Physics
306VikramRao9.82024-01-15 10:45:00History
307RiyaPatel9.62024-01-15 14:30:00English
308ManavGupta7.852024-01-15 7:15:00Mathematics

Program Table

STUDENT_REF_IDPROGRAM_NAMEPROGRAM_START_DATE
301Data Science2024-01-15 0:00:00
302Mathematics2024-01-15 0:00:00
308Mathematics2024-01-15 0:00:00
305Physics2024-01-15 0:00:00
304Chemistry2024-01-15 0:00:00
307Psychology2024-01-15 0:00:00
306History2024-01-15 0:00:00
303Biology2024-01-15 0:00:00

Scholarship Table

STUDENT_REF_IDSCHOLARSHIP_AMOUNTScholarship Table
30155002022-02-10 0:00:00
3024800 2022-03-18 0:00:00
30332002022-05-25 0:00:00
30446002022-06-15 0:00:00
30552002022-04-20 0:00:00
30660002022-07-10 0:00:00
3075300 2022-08-18 0:00:00
30840002022-09-25 0:00:00

1. Create a SQL query to retrieve "FIRST_NAME" from the Student table in uppercase, and utilize the ALIAS name as STUDENT_NAME.

You can use the SQL query below to answer this SQL query interview question that retrieves the “FIRST_NAME” from the “Student” table, converts it to upper case using the UPPER() function, and assigns it an alias name “STUDENT_NAME” for clarity in the result. This makes the output column name “STUDENT_NAME” instead of “FIRST_NAME”.

SQL query: 

SELECT UPPER(FIRST_NAME) AS STUDENT_NAME

FROM Student;

Output: 

STUDENT_NAME
Aarav
DIYA
SIDDHARTH
PRIYA
AAROHI
VIKRAM
RIYA
MANAV

2. Write a SQL query that prints the first three characters of FIRST_NAME from the Student table.

When the interviewer wants to know if you are aware of the SUBSTRING function, he might ask these types of SQL queries interview questions. Here is an explanation SQL query with output to answer these types of SQL queries interview questions:

The SQL query below selects the first three characters of the FIRST_NAME column from the “Student” table using the SUBSTRING function. This function is used to extract a substring starting from the first character of the name up to three characters.

SQL query

SELECT SUBSTRING(FIRST_NAME, 1, 3) AS First_Three_Chars

FROM Student;

Output:

First_Three_Chars
Aar
Diy
Sid
Pri
Aar
Vik
Riy
Man

3. Write a SQL query to find the location of the alphabet ('a') in the first name column 'Arav' of the Student table.

To find the position of the letter ‘a’ in the first name column of the Student table, we can use the SQL function INSTR (or POSITION in some databases). That is how you can showcase your expertise with the INSTR function to resolve this SQL queries interview question. This function returns the position of the first occurrence of the specified character in a string. Below is the SQL query for finding the location of ‘a’ in the first name ‘Aarav’ from the Student table.

SELECT STUDENT_ID, FIRST_NAME, INSTR(FIRST_NAME, ‘a’) AS Position_of_a

FROM Student

WHERE FIRST_NAME = ‘Aarav’;

Output:

STUDENT_IDFIRST_NAMETable Position_of_aHeader
301Aarav1

4. Develop an SQL query to retrieve the unique values of MAJOR Subjects from the Student table and report their length.

To solve this SQL queries interview quesiton, we need to retrieve the unique values of the MAJOR column from the Student Table and determine the length of each major’s name. We can use the DISTINCT keyword to get unique values and the LENGTH() function to calculate the length of each major’s name.

SQL query: 

SELECT DISTINCT MAJOR, LENGTH(MAJOR) AS MAJOR_LENGTH

FROM Student_Table;

Output

MAJORMAJOR_LENGTH
Data Science 12
Mathematics11
Biology7
Chemistry9
Physics7
History7
Data Science 7

5. Create a SQL query that prints FIRST_NAME from the Student table, replacing 'a' with 'A'.

The SQL query below selects the FIRST_NAME from the “Student Table” and replaces all occurrences of the letter ‘a’ with ‘A’ using the REPLACE() function. This ensures that every ‘a’ in the first names is converted to ‘A’ in the output. Use SQL query given below to resolve these interview questions.

SQL query: 

SELECT REPLACE(FIRST_NAME, ‘a’, ‘A’) AS FIRST_NAME

FROM Student;

Output:

FIRST_NAME
AArAv
DiyA
SiddhArth
PriyA
Aarohi
VikrAm
RiyA
MAnAv

6. Create a SQL query to print information about students whose FIRST_NAME ends with 'a' and contains six alphabets.

To find students whose FIRST_NAME ends with the letter ‘a’ and contains exactly six alphabets, we can use the WHERE clause in SQL query with string functions such as LIKE and LENGTH and resolve this interview quesiton. The LIKE operator will help us filter names that end with ‘a’, and the LENGTH function will ensure the name has six characters.

SQL query: 

SELECT STUDENT_ID, FIRST_NAME, LAST_NAME, GPA, ENROLLMENT_DATE, MAJOR

FROM Student_Table

WHERE FIRST_NAME LIKE ‘_____a’

AND LENGTH(FIRST_NAME) = 6;

Output will be none. 

7. Build a SQL query to print information about students with GPAs between 9.00 and 9.99.

The SQL query below returns information on students with GPAs between 9.00 and 9.99. It picks appropriate columns from the “Student Table” depending on the GPA requirement. This will exclude students with GPAs within the stated range.

SQL query: 

SELECT STUDENT_ID, FIRST_NAME, LAST_NAME, GPA, ENROLLMENT_DATE, MAJOR

FROM StudentTable

WHERE GPA BETWEEN 9.00 AND 9.99;

Output

STUDENT_IDFIRST_NAMELAST_NAMEGPAENROLLMENT_DATEMAJOR
304PriyaVerma9.452024-01-15 11:00:00Chemistry
306VikramRao9.82024-01-15 10:45:00History
307RiyaPatel9.62024-01-15English

8. Create a query to retrieve the last record from the Scholarship table.

To resolve SQL queries interview questions like retrieving the last data we can order the records by the SCHOLARSHIP_DATE in descending order and then limit the result to just one row, ensuring we get the most recent entry. 

SQL query: 

SELECT *

FROM ScholarshipTable

ORDER BY SCHOLARSHIP_DATE DESC

LIMIT 1;

Output

30840002022-09-25 0:00:00

9. Write an SQL query to retrieve the second-highest value of an integer field from the student table.

To get the second-highest value of an integer field from a table, we can use the SQL query with the MAX function and a subquery and answer this interview quesiton. The subquery will exclude the maximum value, allowing us to get the second-highest value. For example, to find the second-highest GPA from the Student Table, we will use the following query:

SELECT MAX(GPA) AS second_highest_gpa

FROM StudentTable

WHERE GPA < (SELECT MAX(GPA) FROM StudentTable);

Output:

second_highest_gpa
9.6

10. Use the WHERE clause to create a query to view a specific record from the table

In SQL, the WHERE clause is used to filter records that meet specific conditions. We will apply the WHERE clause to resolve this interview question for SQL queries and you can retrieve a particular record from a table based on criteria such as student ID, GPA, or name.

Here is an SQL query that retrieves the record of a student whose STUDENT_ID is 301 from the Student Table:

SELECT *

FROM Student_Table

WHERE STUDENT_ID = 301;

Output:

STUDENT_IDFIRST_NAMELAST_NAMEGPAENROLLMENT_DATEMAJOR
301AaravMehta8.9 2024-01-15 9:00:00 Data Science

11. Create a SQL query to retrieve the number of students with the Major Subject 'Mathematics’

To count the number of students who have “Mathematics” as their major, we can use a SELECT query with the WHERE condition to filter by the major. The COUNT() function will then give the number of students matching the condition and can answer these SQL query interview questions. 

SQL query: 

SELECT COUNT(*) AS number_of_students

FROM Student_Table

WHERE MAJOR = ‘Mathematics’;

Output will be 2. 

12. Create a SQL query to retrieve students' full names with GPA >= 8.5 and <= 9.5.

The SQL query below retrieves the full names (first and last names) of students who have a GPA between 8.5 and 9.5 (inclusive). This condition filters students within the specified GPA range from the “Student Table.”

SQL query:

FIRST_NAMELAST_NAME
AaravMehta
DiyaKapoor
PriyaVerma
AarohiSharma

SQL query: 

WITH NumberedRows AS (

    SELECT STUDENT_ID, FIRST_NAME, LAST_NAME, GPA, ENROLLMENT_DATE, MAJOR,

           ROW_NUMBER() OVER (ORDER BY STUDENT_ID) AS RowNum

    FROM Student

)

SELECT STUDENT_ID, FIRST_NAME, LAST_NAME, GPA, ENROLLMENT_DATE, MAJOR

FROM NumberedRows

WHERE RowNum % 2 = 1;

If you have good experience and applied for an interview you might be asked sql interview queries for experienced professionals. Here is the explanation and output:

    • The ROW_NUMBER() function assigns sequential row numbers to each record based on STUDENT_ID ordering.
    • We then filter the rows where the RowNum is odd (RowNum % 2 = 1).
STUDENT_IDFIRST_NAMELAST_NAMEGPAENROLLMENT_DATEMAJOR
301Aarav Mehta8.92024-01-15 9:00:00Data Science
303SiddharthJoshi7.2024-01-15 10:15:00Biology
305 Aarohi Sharma8.52024-01-15 9:30:00Physics
307RiyaPatel9.62024-01-15 14:30:00English

14. Create an SQL query to display only odd rows from the Student table.

SQL query: 

SELECT * 

FROM Student 

WHERE MOD(STUDENT_ID, 2) = 0;

Here is an explanation to answer these types of SQL queries interview questions:

    • The MOD(STUDENT_ID, 2) function returns the remainder when the STUDENT_ID is divided by 2.
    • The query selects all rows where the STUDENT_ID is even (i.e., the remainder is 0).

Output:
STUDENT_IDFIRST_NAMELAST_NAMEGPAENROLLMENT_DATEMAJOR
302DiyaKapoor8.752024-01-15 8:45:00Mathematics
304PriyaVerma9.452024-01-15 11:00:00Chemistry
306VikramRao9.82024-01-15 10:45:00History
308ManavGupta7.852024-01-15 7:15:00Mathematics

15. Create a SQL query to find the nth (say, n=5) highest GPA in a table.

SQL query: 

SELECT GPA

FROM (

    SELECT GPA, DENSE_RANK() OVER (ORDER BY GPA DESC) AS rank

    FROM Student_Table

) AS Ranked_GPA

WHERE rank = 5;

Here is an explanation to answer these types of SQL queries interview questions:

    1. The query uses the DENSE_RANK() function to assign a rank to each unique GPA in descending order (highest to lowest).
    2. Then, we filter the results to return the GPA with a rank of 5, which corresponds to the 5th highest GPA in the table.

Output will be 8.50.

16. Create a SQL query to find the fifth highest GPA without using the LIMIT keyword.

SQL query: 

SELECT GPA

FROM Student_Table s1

WHERE 4 = (SELECT COUNT(DISTINCT s2.GPA)

           FROM Student_Table s2

           WHERE s2.GPA > s1.GPA);

Here is an explanation to answer these types of SQL queries interview questions:

    1. The query compares each GPA with other distinct GPA values in a subquery. The subquery counts how many distinct GPAs are greater than the current row’s GPA.
    2. By ensuring that exactly four GPAs are greater, the outer query returns the fifth-highest GPA. This avoids the use of LIMIT.

Output: The fifth highest GPA is 8.75

17. Create a SQL statement that uses a subquery to display the second highest GPA from a Student table.

SQL query: 

SELECT MAX(GPA) AS Second_Highest_GPA

FROM Student

WHERE GPA < (SELECT MAX(GPA) FROM Student);

Here is an explanation to answer these types of SQL queries interview questions:

    1. The sub-query (SELECT MAX(GPA) FROM Student) fetches the highest GPA from the Student table.
    2. The outer query then retrieves the maximum GPA that is less than the highest GPA, which gives the second-highest GPA.

This result comes from the Student Table, where the second highest GPA is 9.60 belonging to Riya Patel.

18. Write a SQL query to retrieve the MAJOR subjects with fewer than four persons.

SQL query: 

SELECT MAJOR, COUNT(STUDENT_ID) AS Student_Count

FROM StudentTable

GROUP BY MAJOR

HAVING COUNT(STUDENT_ID) < 4;

Here is an explanation to answer these types of SQL queries interview questions:

    1. The query groups the students by their MAJOR and counts how many students are enrolled in each subject using the COUNT function.
    2. The HAVING clause filters the result to only show MAJOR subjects where the count of students is fewer than four.

Output:
MAJORStudent_Count
Data Science1
Biology1
Chemistry1
Physics1
History1
English1

19. Create an SQL query to display the last record in a table

SQL query: 

SELECT *

FROM StudentTable

ORDER BY STUDENT_ID DESC

LIMIT 1;

Here is an explanation to answer these types of SQL queries interview questions:

    1. The ORDER BY STUDENT_ID DESC ensures the records are sorted in descending order by the STUDENT_ID column, making the last record appear first.
    2. LIMIT 1 ensures that only the first record from the sorted result is returned, which is effectively the last record of the original table.

Output:
STUDENT_IDFIRST_NAMELAST_NAMEGPAENROLLMENT_DATEMAJOR
308ManavGupta7.852024-01-15 7:15:00Mathematics

20. Create a SQL query to retrieve the last five records from a table.

SQL query: 

SELECT *

FROM Student_Table

ORDER BY STUDENT_ID DESC

LIMIT 5;

Here is an explanation to answer these types of SQL queries interview questions:

    1. This query selects all columns from the “Student Table” and orders the records by STUDENT_ID in descending order (from highest to lowest).
    2. The LIMIT 5 clause restricts the result to the last five records based on the descending order, showing the most recent entries.

Output:
STUDENT_IDFIRST_NAMELAST_NAMEGPAENROLLMENT_DATEMAJOR
308ManavGupta7.852024-01-15 7:15:00Mathematics
307RiyaPatel 9.62024-01-15 14:30:00English
306VikramRao9.82024-01-15 10:45:00History
305AarohiSharma8.52024-01-15 9:30:00Physics
304PriyaVerma9.452024-01-15 11:00:00Chemistry

Final Thoughts

Anyone interested in working as a data analyst, data engineer, or business analyst must be able to answer SQL queries interview questions well. This resource includes a thorough set of SQL queries interview questions and answers, giving you the tools you need to succeed in your interviews. To learn further Jaro Education offers comprehensive, industry-relevant courses such as Executive Programme in Full Stack Web Development that simplify learning SQL queries, helping you build practical skills through hands-on experience. With expert guidance, you’ll master SQL techniques essential for excelling in data-driven roles.

You may confidently demonstrate your SQL proficiency—a key ability that facilitates data processing, analysis, and decision-making across tech-driven industries—by becoming familiar with and practicing these queries. With proper preparation, you will be well-equipped to stand out in your interview and land your chosen position.

Frequently Asked Questions

Where can I find real-world SQL problems to practice?

You can find real-world SQL problems on platforms like LeetCode, HackerRank, and Mode Analytics. Many of these sites provide hands-on exercises with sample datasets. Additionally, you can practice on public databases like Kaggle to sharpen your skills.

What are some common SQL queries interview questions for beginners?

Common beginner SQL queries questions include basic queries such as SELECT, INSERT, UPDATE, and DELETE commands, understanding PRIMARY KEY and FOREIGN KEY, and basic joins like INNER JOIN and LEFT JOIN. You should also know how to filter data using WHERE and aggregate it with GROUP BY.

What are some common SQL queries interview questions for intermediate practitioners?

Intermediate SQL questions often involve advanced JOIN types, subqueries, window functions, and working with indexes. You may also be asked to optimize queries for performance and demonstrate your understanding of transactions and normalization concepts. 

How should I prepare for an SQL interview?

To prepare a review of key SQL concepts such as query syntax, joins, subqueries, and indexing. Practice solving real-world problems on coding platforms and brush up on both theoretical and practical SQL knowledge.

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