Aggregate function and other columns

Question

Is it possible for a SQL query to return some normal columns and some aggregate ones?

like :

Col_A | Col_B | SUM
------+-------+------
   5  |   6   |  7

Answer 1

You should use the group by statement.

The GROUP BY statement is used in conjunction with the aggregate functions to group the result-set by one or more columns.

For example:

SELECT column_name, aggregate_function(column_name)
FROM table_name
WHERE column_name operator value
GROUP BY column_name

You can see a complete example here.