The GROUP BY clause groups rows that have the same values in one or more specified columns. Aggregate functions such as COUNT, SUM, and AVG can then calculate results separately for each group.
Business analysis often requires comparisons between groups, such as sales by region, employees by department, or transactions by month. GROUP BY makes these summaries possible.
A sales manager wants to know total sales for each region. GROUP BY Region creates a separate group for each region, allowing SUM to calculate sales for every region.
SELECT
Region,
SUM(SalesAmount) AS TotalSales
FROM Sales
GROUP BY Region;GROUP BY is heavily used in sales reports, regional analysis, department reporting, customer analysis, financial summaries, and dashboard datasets.
- GROUP BY creates groups of rows.
- It is commonly used with aggregate functions.
- Multiple columns can be used for grouping.
- It is useful for summary reports.
- GROUP BY results can be filtered using HAVING.
What does GROUP BY do?
GROUP BY groups rows with matching values so aggregate calculations can be performed for each group.
Can GROUP BY use multiple columns?
Yes. Multiple columns can be specified to create more detailed groups.