PostgreSQL Constraints Explained | NOT NULL, UNIQUE, CHECK

📘 Download PostgreSQL Notes: https://kodyfier.com/notes/database/p... ------------------------------------------------------- In this PostgreSQL tutorial, you'll learn how Constraints help maintain data integrity and prevent invalid data from entering your database. We cover the most commonly used PostgreSQL constraints including NOT NULL, UNIQUE, and CHECK constraints with practical examples and real-world scenarios. You'll also learn how to inspect existing constraints, add new constraints to existing tables using ALTER TABLE, and follow industry best practices while designing database schemas. Whether you're preparing for interviews, learning backend development, or becoming a PostgreSQL expert, this lesson will help you build more reliable and professional databases. PostgreSQL constraints are one of the most searched and essential database topics because they enforce data validation directly at the database level. ------------------------------------------------------------------------------------ 🔗 Useful Playlists 📘 Next.js Full Stack Playlist:    • Next.JS Full Course Tutorial in Hindi   ⚛️ React.js Playlist:    • React.js v19 Tutorials in Hindi - 2025   💻 TypeScript Playlist:    • Typescript Tutorial for Beginners in Hindi   ------------------------------------------------------------------------------------ 💸 Get All My YouTube Videos' Source Code for just ₹199! Grab Now - https://thapatechnical.shop/source-code 📺 Watch the complete Node.JS Playlist here :   • Node JS Tutorial for Beginners in Hindi - ...   🔥 Access Source Code, PPT & Notes here for Free : https://www.thapatechnical.com/2024/1... ------------------------------------------------------------------------ 🚀 Boost Your Skills with these Pre-Requisite Videos: 🔗 Best HTML Course -    • HTML Complete Tutorial for Beginners in Hi...   🔗 Best CSS Course -    • Complete CSS Tutorial for Beginners in Hin...   🔗 JavaScript Basics Course Part 1 -    • JavaScript Full Course Tutorial for Beginn...   🔗 JavaScript Advanced Course Part 2 -    • JavaScript Advanced full Course Tutorial🔥1...   ------------------------------------------------------------------------ 💸 Build Your Own E-commerce Website for Free! - https://www.thapatechnical.com/2024/0... ------------------------------------------------------------------------ ✌️ Join Us! 🚀 Become a Member: Unlock perks, free source code, and more Join Now :    / @thapatechnical   📷 Connect on Instagram:   / thapatechnical   🗨️ Join Our Discord Server: Hang out with fellow programmers Discord Link:   / discord   ------------------------------------------------------------------------ ⌛TIMELINE⏳ 0:00 Introduction to PostgreSQL Constraints 0:15 Types of Constraints in PostgreSQL 3:40 Constraints Syntax Explained 6:00 Best Practices Every Developer Should Know 9:35 Practice Questions for You 9:55 Get Source Code for Free 10:40 Query 1 - NOT NULL Constraint Example 12:29 How to Check Constraints in a Table 13:21 Query 2 - UNIQUE Constraint Example 15:10 Important Concept Explained 18:00 Adding Constraints to Existing Columns 19:29 Query 3 - CHECK Constraint Example 22:22 Query 4 - Practical Scenario 24:10 Conclusion & Next Steps