MAX function [Aggregate]

MAX( [ ALL | DISTINCT ] expression )

MAX( [ ALL ] expression ) OVER ( window-spec )

window-spec : see Syntax 2 instructions in the Remarks section below

[ ALL ] 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.

The same data type as the argument.

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 of the WINDOW clause. See WINDOW clause.

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

For more information about specifying a window specification in an OVER clause, see Window definition: Inlining using the OVER clause and WINDOW clause.

This function supports NCHAR inputs and/or outputs.

For simple comparisons of two expressions, you can also use the GREATER function.

SQL/2008 Core feature. When used as a window function (Syntax 2), MAX comprises part of optional SQL/2008 language feature T611, "Basic OLAP operations".
The ability to specify DISTINCT over an expression that is not a column reference comprises part of optional SQL language feature F561, "Full value expressions". SQL Anywhere also supports SQL/2008 language feature F441, "Extended set function support", which permits operands of aggregate functions to be arbitrary expressions possibly including outer references to expressions in other query blocks that are not column references.

SQL Anywhere does not support optional SQL/2008 feature F442, "Mixed column references in set functions". SQL Anywhere does not permit the arguments of an aggregate function to include both a column reference from the query block containing the MAX function, combined with an outer reference.

For an example, see AVG function [Aggregate].

Aggregate functions and outer references

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

SELECT MAX( Salary )
FROM Employees;

MAX function [Aggregate]

Syntax 1

Syntax 2

Parameters

Returns

Remarks

See also

Standards and compatibility

See also

Example