Expressions.Case expression
            A function selecting a value conditionally
Format
{ Simple case |
Remarks
A string function returns a string value and can be any one of the following:- A CASE operation selecting one from a number of alternative values depending on some condition. Refer to Simple case and Searched case for more details.
 - A NULLIF function to return either the first value or NULL. Refer to Case abbreviation NULLIF for more details.
 - A COALESCE function to return the first nonnull value from a number of alternatives. Refer to Case abbreviation COALESCE for more details.