Examples
A. Use a SELECT statement with a simple CASE function
Within a SELECT statement, a simple CASE function allows only an equality check; no other comparisons are made. This example uses the CASE function to alter the display of book categories to make them more understandable.

USE pubs
GO
SELECT   Category =
     CASE type
        WHEN 'popular_comp' THEN 'Popular Computing'
        WHEN 'mod_cook' THEN 'Modern Cooking'
        WHEN 'business' THEN 'Business'
        WHEN 'psychology' THEN 'Psychology'
        WHEN 'trad_cook' THEN 'Traditional Cooking'
        ELSE 'Not yet categorized'
     END,
  CAST(title AS varchar(25)) AS 'Shortened Title',
  price AS Price
FROM titles
WHERE price IS NOT NULL
ORDER BY type, price
COMPUTE AVG(price) BY type
GO