创建一个显示以前汇率的列

Question

我正在创建一个将显示旧地址的列。每当更新地址时，旧地址将在新地址生效的前一天过期，并且新地址将添加具有相同帐号的新行（例如：旧地址将显示：从：10/01 /2020 To: 12/31/2021 and the new address From: 01/01/2022 To: 12-31-9999).我试图为 SQL 中的每个帐号并排显示新旧地址，但我得到的是零。

示例数据

AccountNumber	Address	ValidFrom	ValidTo
4895626	720 Main	10/01/2020	12/31/2021
9794651	158 4th St	09/29/2002	12/19/2020
4895626	5986 9th Ave	01/01/2022	12/31/9999

期望的结果

AccountNumber	Address	ValidFrom	ValidTo	PreviousAddress
4895626	720 Main	10/01/2020	12/31/2021	0
9794651	158 4th St	09/29/2002	12/19/2020	0
4895626	5986 9th Ave	01/01/2022	12/31/9999	720 Main

DECLARE @PreviousValidTo DATE;
SELECT @PreviousValidTo = DATEADD(DAY, -1, Z.ValidFrom)
FROM Address.NewAddress Z
SELECT Address, ValidFrom, ValidTo
CASE
            WHEN @PreviousValidTo = C.ValidFrom
            THEN C.Address
            ELSE 0
            END AS PreviousAddress
FROM Address.NewAddress C

Answer 1

也许你可以使用 lag

select *,
  Lag(address,1,'0') over(partition by accountnumber order by validto) PreviousAddress
from address.NewAddress

创建一个显示以前汇率的列

Creating a column that'll show previous rates

sql

sql-server

dateadd

datahistory