SUM function [Aggregate]

Returns the total of the specified expression for each group of rows.

Syntax 1
SUM( expression | DISTINCT expression )
Syntax 2
SUM( expression ) OVER ( window-spec )
window-spec : see Syntax 2 instructions in the Remarks section below
Parameters
  • expression   The object to be summed. This is commonly a column name.

  • DISTINCT expression   Computes the sum of the unique values of expression in the input.

Remarks

Rows where the specified expression is NULL are not included.

Returns NULL for a group containing no rows.

Syntax 2 represents usage as a window function in a SELECT statement. As such, elements of window-spec can be specified either in the function syntax (inline), or in conjunction with a WINDOW clause in the SELECT statement. See the window-spec definition provided in WINDOW clause.

For more information about using window functions in SELECT statements, including working examples, see Window functions.

See also
Standards and compatibility
  • SQL/2003   Core feature. Syntax 2 is feature T611.

Example

The following statement returns the value 3749146.740.

SELECT SUM( Salary )
FROM Employees;