判断语句能用sql语句来表达嘛

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

case when A1 < 5000 then A1*0.05

     when A1 > 5000 and A1 <= 10000  then A1*0.1-250

     when A1 > 10000 and A1 <= 30000 then A1*0.2-1250

     when A1 > 30000 and A1 <= 50000 then A1*0.3-4250

     when A1 > 50000 then A1*0.35-6750

end