转载来自：http://blog.sina.com.cn/s/blog_7c5d61f30101cx0q.html
举例1：
使用该查询，得出iFavoriteID,iFavUserType ,cUser,iArticleID,dFavoriteTime五个字段的值:
SELECT iFavoriteID,
CASE
WHEN iFavUserType = 0 THEN '新闻管理员'
WHEN iFavUserType = 1 THEN '商家'
WHEN iFavUserType = 2 THEN '会员'
WHEN iFavUserType = 3 THEN '未注册'
WHEN iFavUserType = 4 then '匿名'
END AS iFavUserType, cUser, iArticleID,
CONVERT(nvarchar(100), dFavoriteTime, 111) AS dFavoriteTime FROM dig_favorite
举例2：
SELECT CASE WHEN `MEMBERTYPE` =1
THEN '参赛队员'
ELSE '指导老师'
END FROM `tab_sign_member`
WHERE 1
