🧹 SQL Query to Remove Duplicate Records While Keeping the Latest Entry Duplicate data is one of the most common problems in database management. In this tutorial, you’ll learn how to remove duplicate records while keeping only the latest entry — based on a timestamp or unique ID. This technique works in MySQL, SQL Server, … Read more
👨💼 SQL Query to Find Employees Who Didn’t Attend Any Training (LEFT JOIN Example) In real-world HR and analytics systems, it’s often necessary to identify employees who have not attended any training programs. This type of query is useful in employee engagement analytics, compliance tracking, and HR dashboards. We’ll use a simple LEFT JOIN approach … Read more
“`html 🏆 SQL Query to Find Top 3 Salaries Without Using LIMIT or TOP (Step-by-Step Example) Finding the top 3 salaries in SQL is a classic interview and practical database problem. Most developers use the LIMIT (MySQL) or TOP (SQL Server) clause — but what if your system doesn’t support them, or you want a … Read more
⚡ SQL Query to Calculate Running Total Without Window Functions (Step-by-Step Example) Calculating a running total (cumulative sum) is a key task in data reporting, especially for business dashboards, financial reports, and time-based analytics. Modern databases offer SUM() OVER() window functions to handle this easily — but what if your system doesn’t support them? Don’t … Read more
🧠 SQL Query to Find Duplicate Records with Different Values (Real-World Example) Data duplication is one of the most common challenges in database management. Often, you’ll encounter duplicate records with mismatched details — such as the same employee ID appearing with different email addresses or contact numbers. These inconsistencies can cause serious reporting errors in … Read more
Top 25 SQL Interview Questions and Answers for 2025 (With Real Examples) Top 25 SQL Interview Questions and Answers for 2025 (With Real Examples) Updated: July 2025 | Estimated Reading Time: 8 mins Preparing for a SQL interview in 2025? Whether you’re aiming for a role as a data analyst, backend developer, or database administrator, … Read more
Top 10 Most Asked SQL Queries in Data Analyst Interviews (With Real-World Examples) SQL is the most crucial skill for data analysts. Whether you’re applying for a junior or senior role, SQL queries are guaranteed to appear in your interview. In this guide, you’ll learn the top 10 SQL queries most frequently asked in data … Read more
Introduction PL/SQL (Procedural Language/Structured Query Language) is an extension of SQL that allows programmers to write procedural code, such as loops, conditional statements, and exception handling. One of the most fundamental operations in any programming language is adding two numbers, and in this guide, we will explore how to achieve this using a PL/SQL program … Read more