如何在oracle/sql中处理每行并将多行合并为一行

我是oracle 11g的新手。我做了一些研究，但没有一个能完全满足我的要求

这是我的桌子

T1

T2。这是一张比例尺

Subject    Weight
Math         2
CS           2.1
History      1.9
Science      2

我希望我的输出是：

T3

Date_    Name   Math   History  CS     Science
2011     AAA            160     178.5
2013     AAA    180             193.2   182

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非常感谢

您正在尝试使用乘法因子进行轴心旋转。下面是一个使用显式聚合处理此问题的方法：

select Date_, Name,
       sum(case when Subject = 'Math' then T1.Mark * T2.Weight end) as Math,
       sum(case when Subject = 'History' then T1.Mark * T2.Weight end) as History,
       sum(case when Subject = 'CS' then T1.Mark * T2.Weight end) as CS,
       sum(case when Subject = 'Science' then T1.Mark * T2.Weight end) as Science
from T1 join
     T2
     on T1.Subjecct = T2.Subject
group by Date_, Name;

select Date_, Name,
       sum(case when Subject = 'Math' then T1.Mark * T2.Weight end) as Math,
       sum(case when Subject = 'History' then T1.Mark * T2.Weight end) as History,
       sum(case when Subject = 'CS' then T1.Mark * T2.Weight end) as CS,
       sum(case when Subject = 'Science' then T1.Mark * T2.Weight end) as Science
from T1 join
     T2
     on T1.Subjecct = T2.Subject
group by Date_, Name;