case Expression for Alternative Representation

Use case expression to represent data in a manner that is more meaningful, for example, to display a phrase rather than a binary (1, 0) setting.

For example, the pubs2 database stores a 1 or a 0 in the contract column of the titles table to indicate the status of the book’s contract. However, in your application code or for user interaction, you may prefer to use the words “Contract” or “No Contract” to indicate the status of the book. To select the type from the titles table using the alternative representation:

select title, "Contract Status" =
        when contract = 1 then "Contract"
        when contract = 0 then "No Contract"
from titles
title                                   Contract Status
-----                                   ---------------
The Busy Executive’s Database Guide     Contract 
Cooking with Computers: Surreptitio     Contract 
You Can Combat Computer Stress!         Contract    
. . . 
The Psychology of Computer Cooking      No Contract 
. . . 
Fifty Years in Buckingham Palace        Contract 
Sushi, Anyone?                          Contract 
(18 rows affected)