行转列UNPIVOT列转行PIVOT，注意是Oracle 11g及以后才支持

Posted 2020-10-28 zzwo

现有一表，原始数据如下：

现在需要查询出如下结果（条件是：[80,~]优秀，[60,80)及格，[~,60)不及格）：

先用UNPIVOT对原始表进行转换，列转行

select * from CB_SHANGCICB UNPIVOT (cj for kc in ("语文","数学","英语")) ，结果如下：

再对cj进行区间匹配

with tt as (select * from score unpivot (cj for kc in ("语文","数学","英语")))

select kc,(case when cj>=80 then ‘优秀‘ when cj>=60 then ‘及格‘ else ‘不及格‘ end) cj from tt；

执行结果如下：

然后使用PIVOT进行列转行

select * from (

with tt as (select * from score unpivot (cj for kc in ("语文","数学","英语")))

select kc,(case when cj>=80 then ‘优秀‘ when cj>=60 then ‘及格‘ else ‘不及格‘ end) cj from tt

) PIVOT max(cj) for kc in (‘语文‘ as "语文",‘数学‘ as "数学",‘英语‘ as "英语") ，红色背景部分必须为聚合函数；