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.

Returns

INTEGER

DOUBLE

NUMERIC

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;