价值两天

Question

我有一张表格，显示某一天帐户的利率。我想查询一天的利率和第二天的利率。具体来说，我正在寻找利率从一天到下一天变化的账户。

我的数据看起来像这样

帐号/贷款号码/日期/利率
1234/5656 / 1/1/18/12％
1234/5656 / 1/2/18 / 12％
1234/5656 / 1/3/18/0％
1234/5656 / 1/4/18/0％

我希望查询只返回利率从12％变为0％的两天。

根据以上数据，它将返回以下内容：

帐号/贷款号码/日期/利率/次日/次日费率
1234/5656 / 1/2/18 / 12％/ 1/3/18 / 0％

我正在使用的代码（见下文）多次返回相同的日期，并通过我无法识别的某些因素修改“次日费率”。

这是我到目前为止所拥有的。

select
tc.loanaccountid AS 'Account'
, l.LoanNumber AS 'Loan Number'
, tc.trialbalancedate AS 'Date'
, tc.interestrate AS 'Interest Rate'
, tb.trialbalancedate AS 'Next Day'
, tb.interestrate AS 'Next Day Rate'


from dbo.dailytrialbalance tc
join dbo.loanaccount l on tc.loanaccountid = l.loanaccountid
left join dbo.dailytrialbalance tb on dateadd(day, 1, tc.trialbalancedate) = 
tb.trialbalancedate


where tc.PortfolioCodeId = '10' 
and tc.interestrate = '0' 
and tb.interestrate > '0'

我还在学习SQL，所以感谢任何帮助。谢谢。

Answer 1

以下是SQL Server 2012以后的LEAD方法。我添加了(SELECT NULL)作为占位符，以便更正确地确定差异，因为您有1/2/18的重复数据：

with cte as(
select
tc.loanaccountid AS 'Account'
, l.LoanNumber AS 'Loan Number'
, tc.trialbalancedate AS 'Date'
, tc.interestrate AS 'Interest Rate'
, NextDay = lead(tc.trialbalancedate) over (partition by tc.loanaccountid order by tc.trialbalancedate, (select null)) 
, NextDayRate = lead(tc.interestrate) over (partition by tc.loanaccountid order by tc.trialbalancedate, (select null)) 
from dbo.dailytrialbalance tc
join dbo.loanaccount l on tc.loanaccountid = l.loanaccountid)

select * 
from cte 
where NextDayRate = 0 and [Interest Rate] != 0

Here is it in action，包含您的测试数据：

declare @testData table (AccountNumber int, LoanNumber int, Date date, InterestRate varchar(3))
insert into @testData
values

(1234,5656,'20180101','12%'),
(1234,5656,'20180102','12%'),
(1234,5656,'20180103','0%'),
(1234,5656,'20180104','0%')



;with cte as(
select
    AccountNumber
    ,LoanNumber
    ,[Date]
    ,InterestRate
    ,NextDay = lead([Date]) over (partition by AccountNumber order by [Date]) 
    ,NextDayRate = lead(InterestRate) over (partition by AccountNumber order by [Date]) 
from @testData)

select * 
from cte 
where NextDayRate = '0%' and InterestRate != '0%'