SQL Fundamentals Quick Start Your First SELECT Query Core Concepts Data Types DDL Operations (Data Definition Language) DML Operations (Data Manipulation Language) Query Filtering Sorting Results Aggregate Functions Basic JOINs Common String Functions Date Functions Subqueries & Nested Queries CASE Statements NULL Handling Distinct & Duplicates Union & Set Operations Window Functions (Introduction) Common SQL Patterns Employee Salaries Problem Sales & Orders Performance Tips Next Steps Learn Advanced SQL including CTEs, complex window functions, and query optimization in the skill. ---