DBMS & SQL Interview Questions: 25 Most Frequently Asked Queries for SDE Roles
By Rohan Verma · Published · 1 min read
Master top 25 SQL query problems and DBMS concepts asked in campus placement drives. Covers Joins, Group By, Subqueries, Indexing, and Normalization.
Mastering SQL & Database Concepts
Database queries are tested in almost every online assessment and technical interview round.
Top SQL Query: Find Nth Highest Salary
-- SQL Query for Nth Highest Salary using DENSE_RANK()
SELECT salary FROM (
SELECT salary, DENSE_RANK() OVER (ORDER BY salary DESC) as rnk
FROM Employee
) WHERE rnk = 2; -- Change N here
ACID Properties Explained
- Atomicity: All statements in a transaction complete successfully or all roll back.
- Consistency: Database constraints remain valid before and after transaction.
- Isolation: Concurrent transactions execute independently without interference.
- Durability: Committed data remains persisted even in crash scenarios.