How do you use GROUP BY?

The basic syntax for GROUP BY in SQL is:

SELECT column1, column2, AGG_FUNC(column3)

FROM table_name

GROUP BY column1, column2;

Here, column1 and column2 are the columns you want to group by, and AGG_FUNC is an aggregate function such as SUM, AVG, COUNT, MAX, or MIN applied to column3. The GROUP BY clause must list all non-aggregated columns in the SELECT clause. The query will return one row for each distinct combination of the grouped columns, with the aggregate value computed for each group.