Question

我有一张桌子

 CMPI_CODE   CMI_CODE CMN_CDTY_MTRL CMPI_PRICE_TYPE   TRM_CODE ENTRY_DATE   USR_CODE CMPI_PRCINX CMPI_ID_REF CMPI_UPDATE_STS CMPI_EFF_DATE
---------- ---------- ------------- --------------- ---------- ---------- ---------- ----------- ----------- --------------- -------------
       141         57           344 AL                         26-MAY-14           0          88         135 N               14-MAY-14     
       135         57           344 AL                         24-MAY-14           0          91         134 N               14-MAY-25     
       134         57           344 AL                         24-MAY-14           0          90         132 N               14-MAY-01     
       132         57           344 PL                         24-MAY-14           0         100             N               14-MAY-01     
       133         58           345 PL                         24-MAY-14           0          55             N               14-MAY-01

我想获得Currnet_Price和Previous Price .. 我的尝试就是这个

  SELECT 
  NTH_VALUE(CMPI_PRCINX,1) FROM LAST OVER (PARTITION BY CMI_CODE ORDER BY CMPI_CODE  ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS cur,
         NTH_VALUE(CMPI_PRCINX,2) FROM LAST OVER (PARTITION BY CMI_CODE ORDER BY CMPI_CODE  ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS PREVIOUS_PRICE
  FROM CMD_MTRL_PRICE_INF B  
  WHERE CMPI_CODE IN (SELECT MAX(CMPI_CODE) FROM CMD_MTRL_PRICE_INF GROUP BY CMI_CODE) ORDER BY CMPI_CODE

输出

CURRENT_PRICE PREVIOUS_PRICE
------------- --------------
          55                
          88

但它应该显示一些像这样的东西

PREVIOUS_PRICE CURRENT_PRICE  
-------------- ------------- 
                          55 
            91            88

需要一些帮助..

Answer 1

您的WHERE子句在应用函数之前过滤掉除了具有max CMPI_CODE的行之外的所有行。因此，您的NTH_VALUE函数无法获取之前的值。

您可以简化它。

NTH_VALUE（CMPI_PRCINX，1）是多余的。
NTH_VALUE（CMPI_PRCINX，2）可以用LAG替换。
您可以使用ROW_NUMBER获取最大CMPI_CODE。
计算完之前的CMPI_PRCINX后，应过滤掉行。

查询：

select cur, prev
from (
        select CMPI_PRCINX cur,
               lag(CMPI_PRCINX) over (partition by CMI_CODE order by CMPI_CODE) prev,
               row_number() over (partition by CMI_CODE order by CMPI_CODE desc) r
        from CMD_MTRL_PRICE_INF
    )
where r = 1;

Fiddle

Answer 2

试试这个

 WITH
PRICEINFO AS(
SELECT B.*,
NTH_VALUE(CMPI_PRCINX,2) FROM LAST OVER (PARTITION BY CMI_CODE ORDER BY CMPI_CODE ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS PREVIOUS_PRICE
FROM CMD_MTRL_PRICE_INF B
)
SELECT PREVIOUS_PRICE,CMPI_PRCINX AS CURRENT_PRICE FROM PRICEINFO
WHERE CMPI_CODE IN (SELECT MAX(CMPI_CODE) FROM CMD_MTRL_PRICE_INF GROUP BY CMI_CODE) ORDER BY CMPI_CODE

从同一行返回错误的前一个和当前值的结果

2 个答案: