如何計算PL / SQL Oracle？

Question

我有2列，每列有2行。 例如

A     B
100   200
200   300

所以我想像這樣計算

Total A          Total B

200-100 = 100   300-200=100

節目

Total A     Total B
100         100

Answer 1

使用MAX()和MIN()聚合函數：

SELECT MAX(A) - MIN(A) AS "Total A",
       MAX(B) - MIN(B) AS "Total B"
FROM TableName

Answer 2

取決於您想要管理的內容。 如果問題與連續行之間的差異有關，則使用lead()或lag()窗口分析函數可能是一種聰明的方法：

with t( a, b ) as
(
 select 100, 200 from dual union all 
 select 200, 300 from dual 
), t2 as
(
select lead(a) over (order by 1) - a as "Total A",
       lead(b) over (order by 1) - b as "Total B",
       row_number() over (order by 1) as rn
  from t        
)
select *
  from t2
 where rn = 1;

Total A  Total B    RN
100      100        1

Answer 3

你可以這樣查詢，

WITH your_table AS 
   (SELECT 100 a, 200 b
      FROM DUAL
     UNION ALL
    SELECT 200 a, 300 b
      FROM DUAL
     ORDER BY 1 DESC)
SELECT SUM(DECODE(ROWNUM, 1, a, -1*a)) TOTAL_A, SUM(DECODE(ROWNUM, 1, b, -1*b)) TOTAL_B
  FROM your_table;

Answer 4

您可以嘗試如下

Select * , `entity1`-`entity2` As `entity3` 
FROM tbl

希望這可以幫助。

Answer 5

在他們的問題中，他們首先想要從最大值中刪除以及由其他人提供給您的解決方案，並且您想要從最后一行/第二行刪除。 因此，第二種方法為您提供了解決方案。 請討論是否有任何疑問。

select sum(Result.A) as A, sum(Result.B) as B, from (
    select top 1 A , B from Table_name order by id_row_order desc
    union all
    select top 1 - A , -B from Table_name order by id_row_order Asc
) as Result