预言机触发器中的子查询

Question

我想在我的触发器中包含条件，基于表中的数据。由于预言机确实允许在触发器中进行子查询，如何实现它。请在下面找到我的代码。Trans_code_master保存有效代码的列表，可以更改这些代码。

提前感谢您的所有帮助。

CREATE OR REPLACE TRIGGER CUST_TRG
BEFORE INSERT OR UPDATE ON CUST_ALL_TRANS
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
WHEN (NEW.TRANSACTION_CODE IN(SELECT TRANS_CODE FROM TRANS_CODE_MASTER))
BEGIN
INSERT INTO CUST_DEPO_TRANS
(
CUST_ID
,AC_ID
,TRANSACTION_CODE
)
VALUES(
:NEW.CUST_ID
,:NEW.AC_ID
,:NEW.TRANSACTION_CODE
)
EXCEPTION
WHEN OTHERS THEN
-- Consider logging the error and then re-raise
RAISE;
END;
/

Answer 1

在when 子句中写入查询是不可能的。尝试以下方式

CREATE OR REPLACE TRIGGER CUST_TRG
BEFORE INSERT OR UPDATE ON CUST_ALL_TRANS
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
DECLARE
V_CNT NUMBER;
BEGIN
SELECT COUNT(1) INTO V_CNT
FROM TRANS_CODE_MASTER 
WHERE TRANS_CODE = NEW.TRANSACTION_CODE;
IF V_CNT > 0 THEN
INSERT INTO CUST_DEPO_TRANS
(
CUST_ID
,AC_ID
,TRANSACTION_CODE
)
VALUES(
:NEW.CUST_ID
,:NEW.AC_ID
,:NEW.TRANSACTION_CODE
)
END IF;
EXCEPTION
WHEN OTHERS THEN
-- Consider logging the error and then re-raise
RAISE;
END;
/