谁能帮我看看这条SQL语句怎么写,急,在线等!

Question

select 
    k1,
    k2,
    decode(sign(to_number(substr(to_char(k5,'yyyymmdd'),7,2))-11),-1,k4,null) a1
    decode(sign(to_number(substr(to_char(k5,'yyyymmdd'),7,2))-10),1,decode(sign(to_number(substr(to_char(k5,'yyyymmdd'),7,2))-21),-1,k4,null),null) a2
    decode(sign(20-to_number(substr(to_char(k5,'yyyymmdd'),7,2))),-1,k4,null) a3
from 表名

Answer 1

--sorry,忘了加逗号了select 
  k1,
  k2,
  decode(sign(to_number(substr(to_char(k5,'yyyymmdd'),7,2))-11),-1,k4,null) a1,
  decode(sign(to_number(substr(to_char(k5,'yyyymmdd'),7,2))-10),1,
              decode(sign(to_number(substr(to_char(k5,'yyyymmdd'),7,2))-21),-1,k4,null),null) a2,
  decode(sign(20-to_number(substr(to_char(k5,'yyyymmdd'),7,2))),-1,k4,null) a3
from 
    表名

Answer 2

楼上的，直接to_char(k5,'DD') 就可以取出日期来了，干嘛还转那么一大圈？

Answer 3

改进一下
select 
  k1,
  k2,
  decode(ceil(to_char(k5,'dd')/11),1,k4,null) a1,
  decode(ceil(to_char(k5,'dd')/10),2,k4,null) a2,
  decode(ceil(to_char(k5,'dd')/10),3,k4,4,k4,null) a3,from 
    表名

Answer 4

错了，第一个应该是除以10select 
  k1,
  k2,
  decode(ceil(to_char(k5,'dd')/10),1,k4,null) a1,
  decode(ceil(to_char(k5,'dd')/10),2,k4,null) a2,
  decode(ceil(to_char(k5,'dd')/10),3,k4,4,k4,null) a3,from