SUM( [ DISTINCT ] expression )

• INTEGER
• DOUBLE
• NUMERIC

Rows where the specified expression is NULL are not included.

Returns NULL for a group containing no rows.

This function can generate an overflow error, resulting in an error being returned. You can use the CAST function on numeric-expression to avoid the overflow error. See CAST function [Data type conversion].

• COUNT function [Aggregate]
• AVG function [Aggregate]

The following statement returns the value 3749146.740.

SELECT SUM( Salary )
FROM Employees;