createorreplacefunctionamountfn
(
    customernum varchar2,
    startdate   date
) returncharis
    v_amount         number;
    v_receipt_amount number;
    refundamount     number;
    lastdebt         number;
begin
    ---------------------------**********得到上月欠款**************-------------------------------
selectsum(nvl(rct.extended_amount_tax, 0)) extended_amount --当前参数日期之前的所有货款
intov_amount
      from(selectctl.customer_trx_line_id,
                   ct.customer_trx_id,
                   ct.initial_customer_trx_id,
                   ct.trx_number,
                   nvl(cux_ar_utl_pkg.get_trx_gl_date(ct.customer_trx_id),
                       ct.trx_date) trx_date,
                   ct.bill_to_customer_id,
                   nvl(ctl.gross_extended_amount, ctl.extended_amount) extended_amount_tax
              fromra_customer_trx_all       ct,
                   ra_customer_trx_lines_all ctl,
                   hz_parties                hpt,
                   hz_cust_accounts          hca,
                   ra_cust_trx_types_all     ctt,
                   mtl_units_of_measure      uom
             wherect.customer_trx_id =ctl.customer_trx_id
               andct.org_id =ctl.org_id
               andct.bill_to_customer_id =hca.cust_account_id
               andhca.party_id =hpt.party_id
               andctt.cust_trx_type_id =ct.cust_trx_type_id
               andctl.line_type !='TAX'
               andctt.type in('INV', 'CM')
               andctt.cust_trx_type_id !=
                   cux_ar_utl_pkg.get_return_commitment_type
               andctl.uom_code =uom.uom_code(+)) rct
     where1=1
       andrct.bill_to_customer_id =
           (selecta.customer_id
              fromar_customers a
             wherea.customer_number =customernum)
       andrct.trx_date <=trunc(startdate, 'month') -1;
    dbms_output.put_line(v_amount ||
                         '：v_amountv_amountv_amountv_amountv_amount');
    selectnvl(sum(acr.functional_amount), 0) --当前参数日期之前的所有应付款
intov_receipt_amount
      fromar_cash_receipts_v acr
     whereacr.gl_date <=trunc(startdate, 'month') -1
       andacr.state !='REVERSED'
       andacr.customer_id =
           (selecta.customer_id
              fromar_customers a
             wherea.customer_number =customernum);
    dbms_output.put_line(v_receipt_amount ||
                         '：v_receipt_amountv_receipt_amountv_receipt_amount');
    selectnvl(sum(araa.amount_applied), 0) --当前参数日期之前的所有退款
intorefundamount
      fromar_cash_receipt_history_all    acrh,
           ar_cash_receipts_all           acr,
           ar_receivable_applications_all araa
     whereacrh.gl_date <=trunc(startdate, 'month') -1
       andacrh.status !='REVERSED'
       andacr.cash_receipt_id =acrh.cash_receipt_id
       andacrh.cash_receipt_history_id =araa.cash_receipt_history_id
       andaraa.applied_customer_trx_id isnull
       andacrh.org_id =acr.org_id
       andaraa.display ='Y'
       andaraa.status ='ACTIVITY'
       andacr.pay_from_customer =
           (selecta.customer_id
              fromar_customers a
             wherea.customer_number =customernum);
    dbms_output.put_line(refundamount ||
                         '：refundAmountrefundAmountrefundAmount');
    lastdebt :=(v_amount -v_receipt_amount +refundamount); --小于当前日期之前的所有货款 减去 小于当前日期之前的所有应付帐款 加 小于当前日期之前的所有退款=上月欠款

returnlastdebt;
end;