Rank() SQL 或类似的东西

Question

你好，有什么方法可以获得这些账户余额，就像我想计算贷方和借方一样

1 - 1000 
2 - 1000-500 = 500
3 - 500-700  = -200

依此类推取决于日期

有什么解决办法比如rank之类的可以帮忙吗？太感谢了/

Answer 1

使用LAG解析函数：

SELECT "Date",
       GREATEST(
         account_balance - LAG(account_balance, 1, 0) OVER (ORDER BY "Date"),
         0
       ) AS credit,
       GREATEST(
         LAG(account_balance, 1, 0) OVER (ORDER BY "Date") - account_balance,
         0
       ) AS debit,
       account_balance
FROM   table_name

其中，对于示例数据：

CREATE TABLE table_name ( "Date", account_balance ) AS
SELECT Date '2021-01-01', +1000 FROM DUAL UNION ALL
SELECT Date '2021-01-02', + 500 FROM DUAL UNION ALL
SELECT Date '2021-01-03', - 200 FROM DUAL;

输出：

Date CREDIT DEBIT ACCOUNT_BALANCE

01-JAN-21 1000 0 1000

02-JAN-21 0 500 500

03-JAN-21 0 700 -200

反方向计算：

SELECT "Date",
       credit,
       debit,
       SUM(credit-debit) OVER (ORDER BY "Date") AS account_balance
FROM   table_name

其中，对于示例数据：

CREATE TABLE table_name ( "Date", credit, debit ) AS
SELECT Date '2021-01-01', 1000,   0 FROM DUAL UNION ALL
SELECT Date '2021-01-02',    0, 500 FROM DUAL UNION ALL
SELECT Date '2021-01-03',    0, 700 FROM DUAL;

输出：

Date CREDIT DEBIT ACCOUNT_BALANCE

01-JAN-21 1000 0 1000

02-JAN-21 0 500 500

03-JAN-21 0 700 -200

db<>fiddle here

Rank() SQL 或类似的东西

Rank() SQL Or Something like that

sql

oracle

rank