Question

此触发器将插入的值传递给过程，该过程将这些值插入另一个表中。我收到了一个变异表错误。我该如何解决这个问题？

CREATE OR REPLACE TRIGGER ADD_INVOICE
BEFORE INSERT OR UPDATE OF APP_NO,C_NO ON APPOINTMENT
FOR EACH ROW
DECLARE
BEGIN

POP_INVOICE(:NEW.APP_NO,:NEW.C_NO,:NEW.APP_DATE);

END;
/

CREATE OR REPLACE PROCEDURE POP_INVOICE(
I_APP_NO IN INVOICE.APP_NO%TYPE,
I_C_NO IN INVOICE.C_NO%TYPE,
I_INV_DATE IN INVOICE.INV_DATE%TYPE)
AS
CURSOR C_POP IS SELECT PRICE FROM TREATMENT T,APPOINTMENT A 
WHERE T.TRT_NO=A.TRT_NO
AND A.APP_NO=I_APP_NO;

V_BILL INVOICE.BILL%TYPE;
BEGIN

OPEN C_POP; 
FETCH C_POP INTO V_BILL;

UPDATE INVOICE
SET INV_NO=INV_IDSEQ.NEXTVAL,
APP_NO=I_APP_NO,
C_NO=I_C_NO,
BILL=V_BILL,
INV_DATE=I_INV_DATE;

END;
/

Answer 1

问题是由触发器本身引用带触发器的表引起的。更改过程以接受TRT_NO作为参数，无需在查询中包含APPOINTMENT，因此将避免变异表异常。根据每个处理的记录数量，您甚至可以将光标合并到UPDATE语句中。

我认为应该这样做，虽然我无法检查数据库。

CREATE OR REPLACE TRIGGER ADD_INVOICE

BEFORE INSERT OR UPDATE OF APP_NO,C_NO ON APPOINTMENT
FOR EACH ROW
DECLARE
BEGIN

POP_INVOICE(:NEW.APP_NO,:NEW.C_NO,:NEW.APP_DATE,:NEW.TRT_NO);

END;
/

修订程序：

CREATE OR REPLACE PROCEDURE POP_INVOICE(
I_APP_NO IN INVOICE.APP_NO%TYPE,
I_C_NO IN INVOICE.C_NO%TYPE,
I_INV_DATE IN INVOICE.INV_DATE%TYPE,
I_TRT_NO IN APPOINTMENT.TRT_NO%TYPE
)
AS

CURSOR C_POP IS SELECT PRICE 
FROM TREATMENT T
WHERE T.TRT_NO = I_TRT_NO;

V_BILL INVOICE.BILL%TYPE;

BEGIN

OPEN C_POP; 
FETCH C_POP INTO V_BILL;
CLOSE C_POP;

INSERT INVOICE
  (inv_no, app_no, c_no, bill, inv_date)
VALUES
  (INV_IDSEQ.NEXTVAL, I_APP_NO, I_C_NO, V_BILL, I_INV_DATE);


END;
/

如何从一个触发器的过程中修复此Mutating表

1 个答案: