17.10 - Example: Using a CASE Expression - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - SQL Functions, Expressions, and Predicates

Advanced SQL Engine
Teradata Database
Release Number
Release Date
July 2021
Content Type
Programming Reference
Publication ID
English (United States)

CASE expressions can be used in place of any value-expressions.

Note that the following example does not specify an ELSE clause. ELSE clauses are always optional in a CASE expression. If an ELSE clause is not specified and none of the WHEN conditions are TRUE, then a null is returned.

   SELECT * 
   FROM t 
   WHERE x = CASE 
              WHEN y=2 
              THEN 1
              WHEN (z=3 AND y=5) 
              THEN 2