Question

我有以下DML语句正常工作，我试图将其变成触发器，但它无效。

DML声明

UPDATE HOLIDAY_RESERVATION R SET SUBTOTAL = 
   NVL((SELECT F.FLI_PRICE FROM FLIGHT F WHERE F.FLI_ID = R.IN_FLIGHT_ID), 0) * NVL(R.IN_FLIGHT_SEATS_NO,0) +
   NVL((SELECT F.FLI_PRICE FROM FLIGHT F WHERE F.FLI_ID = R.OUT_FLIGHT_ID), 0)* NVL(R.OUT_FLIGHT_SEATS_NO,0) +
   NVL((SELECT AC.ACC_PRICEPN FROM ACCOMMODATION AC WHERE AC.ACC_ID = R.ACC_ID), 0);

触发声明

CREATE OR REPLACE TRIGGER HR_SUBTOTAL
BEFORE INSERT OR UPDATE ON HOLIDAY_RESERVATION
FOR EACH ROW
BEGIN
   SELECT 
      NVL((SELECT F.FLI_PRICE FROM FLIGHT F WHERE F.FLI_ID = :NEW.IN_FLIGHT_ID), 0) * NVL(R.IN_FLIGHT_SEATS_NO,0) +
      NVL((SELECT F.FLI_PRICE FROM FLIGHT F WHERE F.FLI_ID = :NEW.OUT_FLIGHT_ID), 0) * NVL(R.OUT_FLIGHT_SEATS_NO,0) +
      NVL((SELECT AC.ACC_PRICEPN FROM ACCOMMODATION AC WHERE AC.ACC_ID = :NEW.ACC_ID), 0)
      INTO :NEW.SUBTOTAL
   FROM DUAL;
END;


Errors for TRIGGER HR_SUBTOTAL:

LINE/COL ERROR
-------- ----------------------------------------------------------------
2/4      PL/SQL: SQL Statement ignored
4/92     PL/SQL: ORA-00904: "R"."OUT_FLIGHT_SEATS_NO": invalid identifier

错误必须在*乘法位中，因为如果我摆脱了乘法位，它的工作原理可能必须用括号或其他选择括起来。

Answer 1

查询中没有为R设置别名。

您应该在select语句中使用：NEW或：OLD选项，如下所示

SELECT 
  NVL((SELECT F.FLI_PRICE FROM FLIGHT F WHERE F.FLI_ID = :NEW.IN_FLIGHT_ID), 0) * NVL(:OLD.IN_FLIGHT_SEATS_NO,0) +
  NVL((SELECT F.FLI_PRICE FROM FLIGHT F WHERE F.FLI_ID = :NEW.OUT_FLIGHT_ID), 0) * NVL(:OLD.OUT_FLIGHT_SEATS_NO,0) +
  NVL((SELECT AC.ACC_PRICEPN FROM ACCOMMODATION AC WHERE AC.ACC_ID = :NEW.ACC_ID), 0)
  INTO :NEW.SUBTOTAL
FROM DUAL;

Oracle触发器出错，标识符无效

1 个答案: