teradata四分位函数（或ANSI SQL）

Question

是否有简单的方法来编写SQL四分位函数？

比方说，我有一个列表 - 在表 （0,0,0,1,1,4,5,7,8,25,100,100,101,260,360,370}

什么是产生一个结果的好方法列值一拉：

select 'Q1', quartile(1,col_name) from table_name 
union 
select 'Q2', quartile(2,col_name) from table_name 
union 
select 'Q3', quartile(3,col_name) from table_name 
union 
select 'Q4', quartile(4,col_name) from table_name 
; 

我还没有发现任何可用于这方面迄今

Answer 1

我不明白你为什么要Q4 :)没有必要使用PERCENTILE_CONT（）函数那你可以用max（）来获取它。

此代码可能会对您有所帮助。

select  'q1' as q 
      , percentile_cont(0.25) within group (order by col) as q_val 
from  table 
union 
select  'q2' as q 
      , percentile_cont(0.5) within group (order by col) as q_val 
from  table 
union 
select  'q3' as q 
      , percentile_cont(0.75) within group (order by col) as q_val 
from  table;