使用列旧值更新列B值

Question

创建以下VendorAccount表

VendorAccount

(Ven_AccountId, 
  Ven_RegNo,   
  Ven_Invoice_RefNo,    
  TotalAmount,
  Paid_ToVen ,    
  Balance
)

在上表中，TotalAmount的值来自另一个表（Vendor_InvoiceDetails）。通过POPUP LOV选择TOTALBALANCE值。

从Pad_TOVEN（TOTALAMOUNT）中减去TotalAMount-Pad_TOVEN金额。当我选择TOTALAMOUNT时，它会给我旧的TOTAL VALUE，如下图所示。

我希望更新该值。当我选择TotalAmount时，它应该在新条目的Ven_Invoice_RefNo列中基于TotalAmount i-e 2300给我新的更新值。下面是触发器，但它有以下错误

错误：PLS-00103: Encountered the symbol "DECLARE" when expecting one of the following: begin function pragma procedure subtype type <an identifier> <a double-quoted delimited-identifier> current curs

触发：

create or replace trigger "VENDORACCOUNT_T2"
BEFORE
insert or update or delete on "VENDORACCOUNT"
for each row
begin
DECLARE new_balance INT; 
DECLARE new_total INT;
DECLARE new_paid INT;

   SELECT balance INTO old_balance,
   total INTO old_total,
       PAID_TOVEN INTO new_paid
   FROM vendoraccount
   WHERE ven_regno = new.ven_regno
   AND VEN_INVOICE_REFNO = new.VEN_INVOICE_REFNO;

   UPDATE vendoraccount SET TOTALAMOUNT = old_total + old_balance - new_paid,
   balance = TOTALAMOUNT - new_paid
   WHERE VEN_REGNO= new.VEN_REGNO
   AND VEN_INVOICE_REFNO = new.VEN_INVOICE_REFNO;

end;

Answer 1

据我所知，有五件事要做：

1. 从“声明”行开始下方移动。
2. 只使用一个“声明”关键字。
3. 声明old_balance。
4. 声明old_total。

5. 只有一个“进入”。

   create or replace trigger "VENDORACCOUNT_T2"
   BEFORE
   insert or update or delete on "VENDORACCOUNT"
   for each row
   DECLARE new_balance INT; 
           new_total INT;
           new_paid INT;
           old_balance INT;
           old_total INT;
   begin
   
   SELECT balance, total, PAID_TOVEN 
   INTO old_balance, old_total, new_paid
   FROM vendoraccount
   WHERE ven_regno = new.ven_regno
   AND VEN_INVOICE_REFNO = new.VEN_INVOICE_REFNO;
   
   UPDATE vendoraccount SET TOTALAMOUNT = old_total + old_balance - new_paid,
   balance = TOTALAMOUNT - new_paid
   WHERE VEN_REGNO= new.VEN_REGNO
   AND VEN_INVOICE_REFNO = new.VEN_INVOICE_REFNO;
   end;
   

Answer 2

您应该在'begin'之前移动声明部分