The Maximum( ) function returns the maximum of a set of values. Null values inside the set will be ignored.
x1, x2, x3,... must be of the same data type. You may pass up to 27 arguments into the function.
Value returned by the function will be of the same type and width of the referencing column.
Maximum(Column('This Rating'),Column('Last Rating'))
The maximum of the columns This Rating and Last Rating will be returned.
Maximum(123, .NULL., 234)
234 will be returned by the above function. .NULL. is ignored.
'B' will be returned by the above function. A+ is smaller than B in alphabetical order.