PostgreSql(Aggregative Functions)

Aggregative Function: Aggregate functions perform calculations on multiple rows and return a single result. They’re essential for: Summarizing data (e.g., total salary, average marks) Analyzing trends (e.g., highest sales, number of employees per department) Filtering grouped results using HAVING #Common SQL Aggregate Functions: SELECT SUM(salary) FROM Employee; SELECT COUNT(*) FROM Employee; SELECT MAX(salary) FROM Employee; SELECT MIN(salary) FROM Employee; Using Aggregate Functions with GROUP BY: SELECT dept_id, AVG(salary) FROM Employee GROUP BY dept_id; Filtering Groups with HAVING SELECT dept_id, COUNT(*) AS emp_count FROM Employee GROUP BY dept_id HAVING COUNT(*) > 5; Shows only departments with more than 5 employees. Bye.. bye..