如何在給定的SQL Server中的每日帳戶余額下計算MTD？

Question

我有一個帶有列[accountid] ， [DateEnding]和[AccountBalance] 。 我需要在使用當月余額減去從上月的每一個最后一天的賬戶余額來計算MTD accountid 。

到目前為止，我有這個：

SELECT [accountid]
      ,[DateEnding]
      ,[AccountBalance]
     ,[AccountBalance MTD Last] = AccountBalance - FIRST_VALUE(AccountBalance) OVER (PARTITION BY accountid, YEAR(DATEADD(mm,-1,[DateEnding])), MONTH(DATEADD(mm,-1,[DateEnding])) ORDER BY [DateEnding] DESC)
FROM [test]
ORDER BY accountid, DateEnding;

Answer 1

在這里，對於每個不同的帳戶，我們都會根據DateEnding找到可用的最新記錄，然后通過減去等於當前天數的天數來找到上個月的最后一天。 例如，2019年4月23日，我們減去23天即可得出2019年3月1日，然后我們可以找到當天的余額。

然后將計算結果放到SELECT中

SELECT Q1.accountid, 
       Q2.DateEnding , 
       Q3.EOMbalance, 
       Q2.LatestBalance, 
       Q2.LatestBalance - Q3.EOMbalance EOM
      FROM (
                SELECT Distinct t1.accountid FROM test t1
           ) Q1
        CROSS APPLY (
                        SELECT TOP 1 t2.AccountBalance LatestBalance, t2.[DateEnding] 
                            FROM test t2 
                            WHERE t2.[accountid] = Q1.accountid 
                            ORDER BY t2.[DateEnding] DESC
                    ) Q2
        CROSS APPLY (
                        SELECT Top 1 t3.AccountBalance EOMbalance 
                            FROM test t3 
                            WHERE t3.[accountid] = Q1.accountid 
                                AND t3.[DateEnding] 
                                      = dateadd(day,0 - DAY(q2.dateending), q2.dateending)
                            ORDER BY t3.[DateEnding] DESC
                    ) Q3

Answer 2

對於這個問題，第一個答案似乎有點復雜（此處不需要“交叉申請”）。

以下內容可能對您來說更容易一些：我首先在子查詢“ a”中查看當日的帳戶余額。 然后，我在子查詢“ b”中查看上個月數據的最后一天的帳戶余額。

然后，只需減去兩個即可顯示MTD增量：

select a.accountid, 
       a.DateEnding, 
       a.AccountBalance as [Current AccountBalance], 
       b.AccountBalance as [EOM prior AccountBalance], --added for clarity
       a.AccountBalance-b.AccountBalance as [AccountBalance MTD Last]
from
    (select accountid, DateEnding, AccountBalance
    from #test 
    where DateEnding = cast(getdate() as date) 
       /* getdate() returns today's date, so this query will also be with respect to today */
    ) a
left join
    (select *
    from #test 
    where DateEnding = DATEADD(MONTH, DATEDIFF(MONTH, -1, GETDATE())-1, -1) 
       /*this returns the last day of last month, always*/
    ) b
    on a.accountid = b.accountid

這是構成此示例數據和#test表的SQL。 只需執行它即可運行自己的“ #test”表：

/*drop table #test
  drop table #dates */
create table #test ([accountid] varchar(255),[DateEnding] date, [AccountBalance] decimal(16,2))
create table #dates (rnk int,dt date)

insert into #dates (dt)
values (cast('20180101' as date))

DECLARE
  @basedate DATE,
  @d   INT
SELECT
  @basedate = '20180101',
  @d = 1

WHILE @d < (select datediff(day,cast('20180101' as date),getdate())+2)  --select datediff(day,getdate(),cast('20180101' as datetime))
BEGIN
  INSERT INTO #dates (dt)
    values (DATEADD(day, 1, (select max(dt) from #dates)))
  set @d = @d+1
END

update a 
set a.rnk = b.rnk
from #dates a
left join (select rank() over (order by dt) rnk,dt from #dates) b on a.dt = b.dt

declare @a int
set @a = 1
declare @i int
set @i = 1
while @a <20
begin
    while @i < (select max(rnk) from #dates)
    begin
        insert into #test
        values (@a,(select dt from #dates where rnk = @i),cast(rand()*1000.0+@i as decimal(16,2)))
        set @i=@i+1
    end
    set @a=@a+1
    set @i = 1
end