The SUM function is used to calculate the total for a column. The syntax is:

SELECT SUM(“column_name”)
FROM
“table_name”

For example, if we want to get the sum of all sales from the following table,

Store Sales Information

we would type in
SELECT SUM(Sales) FROM Store_Information

Result:
SUM(Sales)
$2750

$2750 represents the sum of all Sales entries: $1500 + $250 + $300 + $700.