select
CASE ‘R‘
WHEN ‘Y‘ THEN ‘等于Y‘
WHEN ‘N‘ THEN ‘等于N‘
ELSE ‘不等于Y与N‘
END
select
CASE
WHEN name > ‘A‘ THEN ‘A‘
WHEN name < ‘B‘ THEN ‘B‘
WHEN name = ‘C‘ THEN ‘C‘
ELSE ‘.....‘
END原文：https://blog.51cto.com/gongxi/2489341