MAX function [Aggregate]

Returns the maximum expression value found in each group of rows.

Syntax 1
MAX( expression | DISTINCT expression )
Syntax 2
MAX( expression ) OVER ( window-spec )
window-spec : see Syntax 2 instructions in the Remarks section below
Parameters
  • expression   The expression for which the maximum value is to be calculated. This is commonly a column name.

  • DISTINCT expression   Returns the same as MAX( expression ), and is included for completeness.

Remarks

Rows where expression is NULL are ignored. 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.

This function supports NCHAR inputs and/or outputs.

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

Example

The following statement returns the value 138948.000, representing the maximum salary in the Employees table.

SELECT MAX( Salary )
FROM Employees;