oracle 求占百分比的分析函数 ratio_to_report() over()； 4000


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;

ratio_to_report(a)函数用法

Ratio_to_report() 括号中就是分子，

over() 括号中就是分母 分母缺省就是整个占比

总结：1. 有了ratio_to_report分析函数，我们避免了还需要写分析函数，自己相除的写法，SQL简单实现了。