ratio_to_report 分析函数求占比

drop table test;
 create table test ( name varchar(20), kemu varchar(20), score number );
 insert into test values('testa','yuwen',10);
 insert into test values('testa','英语',100);
 insert into test values('testb','yuwen',60);
 insert into test values('testb','yuwen',120);
 insert into test values('testc','yuwen',40);
 select name, score, ratio_to_report(score) over() as "占所有科目的百分比", ratio_to_report(score) over(partition by kemu) as "占各科目的百分比" from test ;

NAME                      SCORE 占所有科目的百分比 占各科目的百分比
-------------------- ---------- ------------------ ----------------
testa                        10          .03030303       .043478261
testb                        60         .181818182       .260869565
testc                        40         .121212121       .173913043
testb                       120         .363636364        .52173913
testa                       100         .303030303                1



drop table test;

试想下假设我们没有这个分析函数，实现就有可能如下：

 select name,score, (score/sum(score) over()) as "占所有科目的百分比", (score/sum(score) over(partition by kemu)) as "占所有科目的百分比" from test group by name,score,kemu order by 2；