bobbyiliev
docs: Add essential NULL handling functions (IFNULL and COALESCE)
🎯 Add NULL Handling Functions to Essential MySQL Functions Guide
📋 Description
This PR adds a new section on NULL Handling Functions to the Essential MySQL Functions guide, covering two critical MySQL functions that were missing from the documentation:
- IFNULL() - Provides default values for NULL columns
- COALESCE() - Returns the first non-NULL value from multiple expressions
🔧 What's Added
New Section: "NULL Handling Functions" with clear explanations Practical Examples: Real-world SQL code snippets with expected outputs Use Cases: Employee bonus handling, player nickname management, and default value scenarios Consistent Formatting: Follows the existing documentation style and structure
📚 Why This Matters
NULL handling is fundamental in SQL development, and these functions are essential for:
- Preventing unexpected NULL values in query results
- Providing fallback values when data is missing
- Creating robust queries that handle incomplete datasets
- Following SQL best practices for data integrity
🎃 Hacktoberfest 2025
This contribution enhances the learning experience for SQL beginners by filling a genuine gap in the educational content. The added functions are commonly used in production environments and essential for any comprehensive SQL guide.
✅ Checklist
- [x] Content follows existing markdown formatting
- [x] Code examples include proper syntax and table references
- [x] Functions are explained with clear, practical use cases
- [x] Output examples are provided for better understanding
- [x] Section integrates seamlessly with existing content structure
- [x] Added content to
018-essential-mysql-functions.md
