ADVANCED SQL 🔥 Delete Duplicate Emails | 3 SQL Approaches Explained
In this video, you’ll learn how to solve the classic SQL interview problem:
👉 Delete Duplicate Emails while keeping only one record
Duplicate data is a very common issue in real-world databases, and knowing how to remove duplicates efficiently is an important SQL skill.
In this tutorial, we will solve the problem using 3 different SQL approaches.
Topics covered in this video:
✅ Understanding the duplicate email problem
✅ Why duplicates happen in real-world databases
✅ Approach 1: MIN() + NOT IN
✅ Approach 2: EXISTS with Self Join
✅ Approach 3: ROW_NUMBER() with CTE
✅ Step-by-step query explanation
✅ Interview tips and best practices
By the end of this video:
• You’ll understand SQL deduplication techniques
• You’ll know multiple ways to remove duplicate rows
• Your SQL interview preparation will improve
• Your SQL problem-solving skills will become stronger
🎯 Perfect for:
SQL beginners
Data Analysts
Data Engineers
SQL interview preparation
Database developers
👉 Practice the queries yourself
👉 Compare the approaches
👉 Share with your SQL learning community
Visit www.bigdatayatra.com
All views are my own.
SQL Script
CREATE TABLE Customers (
customer_id INT ,
name VARCHAR(50),
email VARCHAR(100)
);
INSERT INTO Customers (customer_id, name, email)
VALUES
(1, 'Ella', '[email protected]'),
(2, 'David', '[email protected]'),
(3, 'Zachary', '[email protected]'),
(4, 'Alice', '[email protected]'),
(5, 'Finn', '[email protected]'),
(6, 'Violet', '[email protected]'),
(Null, 'Sam', Null);