COALESCE Expression Examples | Teradata Vantage - 17.10 - Example: Querying for a Phone Number - Advanced SQL Engine - Teradata Database

The following example returns the home phone number of the named individual (if present), or office phone if HomePhone is null, or MessageService if present and both home and office phone values are null. Returns NULL if all three values are null.

   SELECT Name, COALESCE (HomePhone, OfficePhone, MessageService) 
   FROM PhoneDir;