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A. Using a SELECT statement with a simple CASE function

USE AdventureWorks;
GO
SELECT   ProductNumber, Category =
      CASE ProductLine
         WHEN 'R' THEN 'Road'
         WHEN 'M' THEN 'Mountain'
         WHEN 'T' THEN 'Touring'
         WHEN 'S' THEN 'Other sale items'
         ELSE 'Not for sale'
      END,
   Name
FROM Production.Product
ORDER BY ProductNumber;
GO
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B. Using a SELECT statement with simple and searched CASE function

USE AdventureWorks;
GO
SELECT   ProductNumber, Name, 'Price Range' = 
      CASE 
         WHEN ListPrice =  0 THEN 'Mfg item - not for resale'
         WHEN ListPrice < 50 THEN 'Under $50'
         WHEN ListPrice >= 50 and ListPrice < 250 THEN 'Under $250'
         WHEN ListPrice >= 250 and ListPrice < 1000 THEN 'Under $1000'
         ELSE 'Over $1000'
      END
FROM Production.Product
ORDER BY ProductNumber ;
GO

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C. Using CASE to replace the IIf function that is used in Microsoft Access
SELECT FirstName, Lastname, TelephoneNumber, 
     IIf(IsNull(TelephoneInstructions),"Any time",
     TelephoneInstructions) AS [When to Contact]
FROM db1.ContactInfo 

USE AdventureWorks
GO
SELECT FirstName, Lastname, TelephoneNumber, 'When to Contact' = 
     CASE
          WHEN TelephoneSpecialInstructions IS NULL THEN 'Any time'
          ELSE TelephoneSpecialInstructions
     END
FROM Person.vAdditionalContactInfo