SQL列转换行的两种方法

Posted 2020-09-09

 

--通过MAX...CASE...WHEN...转换列数据
select Student as ‘姓名‘,
MAX(CASE Subject WHEN ‘语文‘ THEN Score ELSE 0 END ) AS ‘语文‘, --替换Subject列数据为Score列数据
MAX(CASE Subject WHEN ‘英语‘ THEN Score ELSE 0 END ) AS ‘英语‘ --替换Subject列数据为Score列数据
from Scores
group by Student
order by Student



 SELECT 
    Student as ‘姓名‘,
    --通过AVG函数转换语文列
    AVG(语文) as ‘语文‘,
    --通过AVG函数转换英语列
    AVG(英语) as ‘英语‘
from Scores
--转换英语和语文的数据为Score列对应的数据
pivot( AVG(Score) for Subject in (语文,英语) )as NewScores

group by Student
order by Student asc