CASE in SQL Server

-- Simple CASE sentence using AdventureWork Database

-- CASE simple. Evaluamos un parametro.

 SELECT
     d.DepartmentID,
     d.Name,
     d.GroupName,
     CASE d.GroupName
         WHEN 'Research and Development' THEN 'Cuarto A'
         WHEN 'Sales and Marketing' THEN 'Cuarto B'
         WHEN 'Manufacturing' THEN 'Cuarto C'
         ELSE 'Cuarto D'
     END AS Tipo_Cuarto
 FROM HumanResources.Department AS d

 DECLARE @valor INT = 0
 SELECT
     d.DepartmentID,
     d.Name,
     d.GroupName,
     CASE
         WHEN d.Name = 'Research and Development' AND @valor = 1 THEN 'Cuarto A'
         WHEN d.Name = 'Sales' OR d.DepartmentID = 4 THEN 'Cuarto B'
         WHEN d.Name LIKE 'T%' THEN 'Cuarto C'
         ELSE 'Cuarto D'
     END AS Tipo_Cuarto
 FROM HumanResources.Department AS d