Group by (SQL)

A 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.

Examples:

Returns a list of Department IDs along with the sum of their sales for the date of January 1, 2000.

SELECT DeptID, SUM(SaleAmount) FROM Sales
WHERE SaleDate = '01-Jan-2000'
GROUP BY DeptID

Common grouping (aggregation) functions include:

• Count - Quantity of matching records (per group)

• Sum - Summation of given value (per group)

• Min - Minimum of given value (per group)

• Max - Maximum of given value (per group)

• Avg - Average of given value (per group)