这是什么语法啊,求解释
以下是全文
-- 23、统计列印各科成绩,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[ <60]
select sc.cid as 课程ID,course.name as 课程名
,SUM(CASE WHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS [100 - 85]
,SUM(CASE WHEN score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS [85-70]
,SUM(CASE WHEN score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS [60 - 70]
,SUM(CASE WHEN score< 60 THEN 1 ELSE 0 END) AS [<60]
from sc,course
where sc.cid=course.cid
group by sc.cid,course.name
我是想知道
CASE WHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0
的语法是怎样的?
CASE
WHEN sex ='1'THEN'男'
WHEN sex ='2'THEN'女'
ELSE'其他'END