更好地编写查询-因为它只适用于通知日期WITH CURDATE中的1行

Question

CREATE TRIGGER NOTICE_ISSUE插入成员后对于每一行插入通知(Ssn、LSSN、NOTICE_TYPE(值(从成员中选择Ssn，其中CURDATE((=NOTICE_DATE(，(从MEMBERS中选择LIB_SSN，其中CURDATE((=NOTICE_DATE(，"续订您的会员资格"(；

Answer 1

如果要复制select查询，最好是这样的：

CREATE TRIGGER NOTICE_ISSUE AFTER INSERT  
ON MEMBERS  
FOR EACH ROW  
INSERT INTO NOTICE (Ssn,LSSN,NOTICE_TYPE)  
SELECT Ssn, LIB_SSN, 'RENEW YOUR MEMBERSHIP'   
FROM MEMBERS  
WHERE CURDATE() = NOTICE_DATE