如何申请一票多票

Question

假设有 5 张发票属于同一客户。

发票ID	金额
1	200
2	400
3	300
4	500

客户支付1000

付款应全部应用于发票 1、2、3 和部分（100 应用于发票 4）

发票ID	金额	付款	未付款
1	200	200	0
2	400	400	0
3	300	300	0
4	500	100	400

尝试循环记录但失败。

kbr = me.payment
Do Until rs.EOF
        
        
        If DLookup("closed", "invoice", "bilid=" & rs!Utility) = 0 And rs!Charges > 0 Then
        
        If kBr >= rs!Charges Then
        DoCmd.RunSQL "insert into advdep ( advbill, advdate, adv_amt, advmode, payref ) values ( " & rs!Utility & " , #" & AdvDate & "#, " & rs!Charges & " , Advmode, payref) " ': DoCmd.RunSQL "update invoice set paidamt=paidamt + " & rs!Charges & ", closed = 1 where bilid=" & rs!Utility & " and closed = 0"
        ElseIf kBr > 0 Then
        DoCmd.RunSQL "insert into advdep ( advbill, advdate, adv_amt, advmode, payref ) values ( " & rs!Utility & " , #" & AdvDate & "#, " & (rs!Charges - kBr) & " , Advmode, payref) " ': DoCmd.RunSQL "update invoice set paidamt=paidamt + " & rs!Charges & ", closed = 1 where bilid=" & rs!Utility & " and closed = 0"
        Else
        Exit Do
        End If
        kBr = kBr - rs!Charges
        rs.MoveNext
    
    Loop

Answer 1

考虑纯 SQL 并通过使用运行总和窗口函数来计算总付款来避免使用 VBA。 MariaDB 支持窗口函数，Access 可以通过引用原始数据库表而不是链接表的直通查询运行更新查询。

请参阅 dbfiddle 演示解决方案，并对数据库结构（即客户、发票和付款表）进行假设。

UPDATE invoices i 
INNER JOIN (
  SELECT 
      i.customer_id,
      i.invoice_id,
      i.amount AS invoice_amount,
      SUM(i.amount) OVER(
          PARTITION BY i.customer_id
          ORDER BY i.invoice_id
      ) AS invoice_running_sum,
      p.amount AS payment

  FROM invoices i
  INNER JOIN payments p
    ON i.customer_id = p.customer_id 
) sub 
  ON i.invoice_id = sub.invoice_id
SET i.paid = (
  CASE 
    WHEN sub.invoice_running_sum < sub.payment
    THEN 0
    ELSE sub.invoice_running_sum - sub.payment
  END
);

在线演示