Basic SQL Interview Questions to Build a Strong Foundation

If you're just starting your database journey or preparing for your first tech interview, mastering the basic SQL interview questions is a crucial step. SQL remains one of the most widely used languages for data querying and manipulation, and interviewers expect you to demonstrate a strong understanding of database fundamentals. This page offers a curated list of basic SQL questions for interview prep—perfect for beginners or anyone revisiting the fundamentals.

What to Expect in Basic DBMS and SQL Interview Questions

Many entry-level interviews start with basic DBMS interview questions that test your understanding of relational databases, normalization, keys, and indexing. You’ll then encounter foundational basic SQL interview questions covering:

• • SELECT, INSERT, UPDATE, DELETE operations
• • Filtering with WHERE, LIKE, and BETWEEN
• • Joins: INNER, LEFT, RIGHT, and FULL
• • Aggregate functions like COUNT, SUM, AVG
• • GROUP BY and HAVING clauses
• • Primary keys vs. foreign keys

These questions are essential for roles involving data analysis, backend development, or database administration.

SQL & PL/SQL Interview Questions You Should Know

While SQL is used for querying and managing data, PL/SQL (Procedural Language/SQL) adds procedural programming capabilities. Our deck also includes SQL PL/SQL interview questions, helping you bridge the gap between simple queries and more advanced database logic. Expect questions such as:

• • Writing stored procedures and triggers
• • Handling exceptions in PL/SQL
• • Using cursors and control structures
• • Understanding packages and functions

In addition, we cover some of the most popular SQL interview questions asked across tech companies—ensuring you’re prepared not just to answer questions, but to demonstrate your ability to think in SQL.

Whether you're reviewing basic SQL questions for interview prep or diving into SQL PL/SQL interview questions, this deck gives you a solid base to build on. Get started and turn your database knowledge into interview confidence.

Yes. WHERE filters before grouping

INSERT INTO B SELECT ... FROM A;

SELECT name

SELECT * FROM Employees

Add an `ORDER BY Salary DESC` clause to the SELECT query.

Use IN with a subquery returning a list.

All rows in the table are updated.

It causes an error; use IN instead.

It combines rows from two or more tables using a related column.

Returns all rows from the left table and matched rows from the right.

A query nested inside another query.

Returns only the rows with matching keys in both tables.

Ascending (ASC) order is the default.

DELETE removes rows selectively; TRUNCATE removes all and is faster.

Functionally the same; IN is shorter.

`COUNT(*)` counts all rows

INNER JOIN gives only matched rows

To filter groups based on aggregated values.

WHERE filters rows before grouping

COUNT(*)

The `WHERE` clause.

AVG()

MAX()

MIN()

SUM()

IN

NOT IN

BETWEEN

LIKE

To group rows that have the same values in specified column(s).

DELETE FROM Orders WHERE status = 'Cancelled';

SELECT * FROM Persons WHERE age > 25 AND city = 'Mumbai';

even if no department exists.

SELECT e.name

SELECT department

SELECT DISTINCT city FROM Customers;

aged 22.

SELECT department

SELECT * FROM Employees WHERE age > 30;

UPDATE Customers SET age = 30 WHERE customer_id = 5;

SELECT COUNT(DISTINCT job_title) FROM Employees;

SELECT * FROM Employees WHERE join_date BETWEEN '2020-01-01' AND '2020-12-31';

SELECT name FROM Employees WHERE manager_id IS NULL;

SELECT * FROM Employees WHERE salary = (SELECT MAX(salary) FROM Employees);

SELECT department

SELECT name FROM Employees WHERE salary > (SELECT AVG(salary) FROM Employees);

SELECT MAX(salary) FROM Employees WHERE salary < (SELECT MAX(salary) FROM Employees);

SELECT salary FROM Employees ORDER BY salary DESC LIMIT 5;

SELECT c.name

UPDATE Employees SET salary = salary * 1.10;