添加perovious場量

Question

請注意，我有2個表：

我想從表中工資trnamt得到更新到tbl_emi在拍攝記錄，但量不應超過EMI量爲每個記錄中，例如在這種情況下，這是在薪水錶量1000應該被添加500到該第一記錄和另外500到第二記錄到tbl_emi表

   tbl_emi 
EMI  DUEDT  REC  Acno 
500 4/30/2014 500  123 
500 5/30/2014 0   123 
500 6/30/2014 0   123 

       slary 
     Acno  Trnamt 
     123   1000 

我用下面的查詢，但它仍然是在tbl_emi tbale中的rec字段加上工資表中的trnamt，但不應超過emi金額。

選擇QUERY1：要創建一個臨時表的accumlated EMI

select a.emi, a.duedt, a.rec, a.acno, coalesce(sum(b.emi),0) as emi_accumulated 
into #accumulated_amount5 
from tbl_emi a 
left join tbl_emi b on a.acno = b.acno and b.duedt < a.duedt 
group by a.emi, a.duedt, a.rec, a.acno; 

QUERY2：要爲工資總額

select a.*, s.RECAMT as salary_amt 
into #accumulated_amount_with_salary5 
from #accumulated_amount5 a 
inner join Tbl_Fin s on a.acno = s.CARDNO; 

更新查詢1創建一個臨時表：要更新REC量

update #accumulated_amount_with_salary5 
set rec = rec + case 
    when salary_amt < emi_accumulated then 0 
    when (salary_amt - emi_accumulated) < emi then salary_amt - emi_accumulated 
    else emi 
end 

更新查詢2

update t 
set lastrecdate=(CAST(GETDATE() AS DATE)), rec = a.rec 
from tbl_emi t 
    inner join #accumulated_amount_with_salary5 a on t.acno = a.acno and t.duedt = a.duedt 
    --Finance 

Answer 1

你可以在工資表中插入觸發器在工資表中的每個插入後，將更新tbl_emi表， 參考如何在SQL服務器觸發器，請參閱http://www.codeproject.com/Articles/25600/Triggers-SQL-Server

Answer 2

假設你之後使用有累積和功能，這是通過計算累計emi值，相較於trnamt相對容易：

with toupdate as (
     select e.*, sum(emi) over (partition by acno order by duedt) as cumemi 
     from tbl_emi e 
    ) 
update toupdate 
    set rec = (case when trnamt > cumemi then emi 
        else trnamt - cumemi + emi 
       end) 
    from toupdate join 
     slary 
     on toupdate.acno = slary.acno and 
      toupdate.cumemi - emi < trnamt; 

即使沒有累計總和，你仍然可以使用相關蘇一樣的東西bqueries。

編輯：

在SQL Server 2008中，你可以表達的累計總和爲：

with toupdate as (
     select e.*, 
      (select sum(e2.emi) 
       from tbl_emi e2 
       where e2.acno = e.acno and 
        e2.duedt <= e.duedt 
      ) as cumemi 
     from tbl_emi e 
    ) 
update toupdate 
    set rec = (case when trnamt > cumemi then emi 
        else trnamt - cumemi + emi 
       end) 
    from toupdate join 
     slary 
     on toupdate.acno = slary.acno and 
      toupdate.cumemi - emi < trnamt;