GROUP BY

Definition

GROUP BY arranges rows that share a value in specified columns into summary rows, typically used together with aggregate functions like COUNT, SUM, or AVG.

Example

SELECT department, COUNT(*) AS emp_count
FROM employees
GROUP BY department;

Why Testers Use It

GROUP BY is useful for verifying dashboards or reports that show totals or counts per category — a tester can run the equivalent grouped query and compare it directly against what the application displays.