SQL Querying: Keys, Null Values, and Essential Functions

Working with databases requires more than just basic select statements; you need to understand how data is structured, constrained, and manipulated. This text-based course guides you through the foundational concepts of database keys, the behavior of null values, and the practical application of essential numeric and text functions. Through clear explanations and structured code snippets, you will learn how to maintain data integrity and transform raw data into meaningful insights. What you'll learn: 1. Understand the critical roles of primary, foreign, and unique keys in database design. 2. Handle null values correctly using modern SQL functions to avoid common logical errors. 3. Apply character and numeric functions to format, clean, and calculate data directly in queries. 4. Write structured SQL queries that ensure data integrity and consistent results. 5. Practice modern query formatting and basic optimization techniques for cleaner code. This course begins with fundamental definitions of database constraints and keys before progressing to hands-on query manipulation and function usage. Designed for beginners who have a basic grasp of SQL syntax, this text-only program requires no advanced programming background. Start mastering the core mechanics of SQL querying today.