Mastering SQL Functions: A Beginner-to-Expert Guide
Mastering SQL Functions: A Beginner-to-Expert Guide In this blog, we’ll explore the most crucial SQL functions and concepts, breaking down each one with simple examples to ensure readers of all experience levels can grasp the material. By the end, you’ll have a solid understanding of functions like GROUP BY , DISTINCT , COUNT , and how different types of JOIN s work, all explained in layman's terms with relatable examples. 1. GROUP BY : Grouping Data by Columns The GROUP BY clause is used when you want to group rows that have the same values in specified columns into aggregated results. When to Use: Use GROUP BY when you want to aggregate data by a particular column, such as summarizing sales per month or counting employees in each department. Example: Imagine you have a table Employees : You want to count how many employees work in each department. Here’s how you can do that: SELECT Department, COUNT(EmpID) AS EmployeeCount FROM Employees GROUP BY Department; Ou...