SQL Constraints Explained Simply (NOT NULL, UNIQUE, PRIMARY KEY, & More!)

🚀 Want to ensure your database stays clean, accurate, and free of bad data? In this video, we break down SQL Constraints—the ultimate guardrails used to enforce data integrity and business rules at the table level! We will look at how constraints prevent duplicate records, block null values, and link tables together securely. Whether you are designing a database from scratch or prepping for an entry-level data engineering interview, mastering constraints is a fundamental skill. What you will learn in this video: 00:00 - Introduction to SQL Constraints & Data Integrity 01:30 - NOT NULL & UNIQUE Constraints (Preventing empty or duplicate entries) 04:00 - PRIMARY KEY vs UNIQUE KEY (The big interview question!) 06:15 - FOREIGN KEY Constraints (Enforcing Referential Integrity between tables) 09:00 - CHECK Constraints (Validating data ranges and business logic) 11:30 - DEFAULT Constraints (Setting fallback values automatically) 13:45 - Live Demo: Creating and altering tables with constraints 💡 Key SQL Code Snippet from the Video: 🔗 HELPFUL LINKS & RESOURCES: • Download the SQL scripts used in this demo: [Insert Link] • Get my Free SQL Database Design Cheat Sheet: [Insert Link] • Subscribe for more clear data tutorials: [Insert Link] If this video helped you understand how to protect your database with constraints, please give it a 👍, drop your questions in the comments, and subscribe for more database tutorials! #SQL #DatabaseDesign #DataAnalytics #DataEngineering #CodingTutorial #LearnSQL #TechInterview #Database