21 What is UNIQUE Key in SQL Server? | Unique Constraint Explained

Complete playlist is here: https://www.youtube.com/playlist?list=PLKFKd7UiwVxMiV9Cy7gaF8A_ylx4FuFA9 In this video, you will learn what a UNIQUE key (UNIQUE constraint) is in SQL Server and how it helps prevent duplicate values in a table. This beginner-friendly tutorial explains how UNIQUE constraints work, how they differ from PRIMARY KEY, and how to use them correctly in real-world databases. 👉 What you will learn What is a UNIQUE key in SQL Server How to create a UNIQUE constraint while creating a table How to add UNIQUE constraint to an existing table Common mistakes and best practices unique key in sql server unique constraint sql server sql server unique key sql unique constraint sql server tutorial