用于创建发票表条目的存储过程

Question

我必须创建一个存储过程来创建发票表条目。该过程应允许用户通过提供新的发票编号x和客户id y来插入记录。日期应为当前系统日期，小计、税金和合计字段应为0。

我已经为这个问题写了这个代码：

SET SERVEROUTPUT ON
CREATE OR REPLACE PROCEDURE InoviceEntry_step1(X in number, Y in number)
as
begin    
  insert into INVOICE(inv_number, cus_code, inv_date,
                      inv_subtotal, inv_tax, inv_total)
  values (X, Y, sysdate, 0, 0, 0);    
end;
/
CALL InoviceEntry_step1 (1009,11111);

调用引发错误：

Error report -
SQL Error: ORA-02291: integrity constraint (USER.SYS_C00109369) violated - parent key not found
ORA-06512: at "USER.INOVICEENTRY_STEP1", line 6
02291. 00000 - "integrity constraint (%s.%s) violated - parent key not found"
*Cause:    A foreign key value has no matching primary key value.
*Action:   Delete the foreign key or add a matching primary key.

我做错了什么？可能有更好的方法吗？

Answer 1

INVOICE表列cus_code上有一个外键，它引用了另一个表中的另一列（我猜是CUSTOMER表的主键或类似的东西）。该表中没有客户id为11111的客户。在运行此过程之前，您需要将值为11111的行添加到另一个表的引用列中。

Answer 2

也许，您面临着无法控制的输入情况。你的程序需要自己控制它们。处理错误有两种方法。

首先，您可以通过Exceptions处理错误。

CREATE OR REPLACE PROCEDURE InoviceEntry_step1
   (X in number, Y in number)
AS
  parent_not_found exception;
  pragma exception_init(parent_not_found, -2291);
BEGIN
  INSERT INTO INVOICE(inv_number, cus_code, inv_date, inv_subtotal, inv_tax, inv_total)
  VALUES(X, Y, SYSDATE, 0, 0, 0);
  COMMIT;
EXCEPTION 
  WHEN parent_not_found
    THEN  DBMS_OUTPUT.PUT_LINE('Error: CUSTOMER_ID = ' || Y || ' is not found.');
  WHEN OTHERS
    THEN DBMS_OUTPUT.PUT_LINE('Error');
END;

其次，你可以自己处理错误。例如，在插入发票之前，我在客户表中检查"cus_code"。

CREATE OR REPLACE PROCEDURE InoviceEntry_step1
   (X in number, Y in number)
AS
 CURSOR c_customer IS (SELECT ID FROM CUSTOMER WHERE ID = Y AND ROWNUM =1);
 v_ID NUMBER;
BEGIN
  OPEN c_customer;
  FETCH c_customer INTO v_ID;
  IF c_customer%NOTFOUND
  THEN
     --Option1: If it shouldn't happend with your designed, you can just let error message without insert data.
     DBMS_OUTPUT.PUT_LINE('Error: CUSTOMER_ID = ' || Y || ' is not found.');
     DBMS_OUTPUT.PUT_LINE('Please create customer profile.');
     --Option2:  You may add customer_id first and insert invoice, if you want but I don't recommend.  
     INSERT INTO CUSTOMER (ID) VALUES(Y);
     DBMS_OUTPUT.PUT_LINE('CUSTOMER_ID = ' || Y || ' has been created.');
     INSERT INTO INVOICE(inv_number, cus_code, inv_date, inv_subtotal, inv_tax, inv_total)
     VALUES(X, Y, SYSDATE, 0, 0, 0);
     DBMS_OUTPUT.PUT_LINE('INVOICE_NO = ' || X || ' has been created.');
  ELSE
     INSERT INTO INVOICE(inv_number, cus_code, inv_date, inv_subtotal, inv_tax, inv_total)
     VALUES(X, Y, SYSDATE, 0, 0, 0);
     DBMS_OUTPUT.PUT_LINE('INVOICE_NO = ' || X || ' has been created.');
  END IF;
  CLOSE c_customer;
  COMMIT;
END;

但是，不要忘记"提交"事务。