GROUP BY statement in SQL specifies that a SQL
SELECT statement returns a list that is grouped by one or more columns, usually in order to apply some sort of aggregate function to certain columns.
Returns a list of Department IDs along with the sum of their sales for the date of January 1, 2000.
a group by statement can use a having clause to filter the number of rows...
Common grouping (aggregation) functions include:
- count(expression) - Quantity of matching records (per group)
- Sum(expression) - Summation of given value (per group)
- Min(expression) - Minimum of given value (per group)
- Max(expression) - Maximum of given value (per group)
- Avg(expression) - Average of given value (per group)