错误(7、11):请- 00201:标识符的NA。TITLE_ID必须声明

triggers are not working as expected and giving compilation error

触发器没有按预期工作并导致编译错误

Error(7,11): PLS-00201: identifier 'NA.TITLE_ID' must be declared

错误(7、11):请- 00201:标识符的NA。TITLE_ID必须声明

here is my trigger

这是我的触发器

CREATE OR REPLACE TRIGGER is_title_available  
BEFORE INSERT ON  rental  
REFERENCING OLD AS o NEW AS na
FOR EACH ROW  
WHEN (na.TITLE_ID > 0)  
DECLARE  
      isavailable  boolean;
      temp number;
      title_not_available EXCEPTION;

BEGIN  
   temp :=na.TITLE_ID;
   if(TITLE_AVAILABLE(temp)) then
   dbms_output.put_line('title available rent entry inserted');
   else 
   raise title_not_available;
   end if;

END;  

and here is my table schema

这是我的表格模式。

CREATE TAble rental(
 BOOK_DATE date DEFAULT sysdate primary key,
 MEMBER_ID int,
 COPY_ID int ,
 TITLE_ID int,
 ACT_RET_DATE date,
 EXPIRY_RET_DATE date DEFAULT sysdate+2    
 );

 ALTER TABLE rental
 ADD CONSTRAINT fk_member_rental
 FOREIGN KEY (MEMBER_ID)
 REFERENCES MEMBER(MEMBER_ID);

1 个解决方案

#1

Please try below way
:na.Title_ID

请尝试以下方式:na.Title_ID

You need to use ':' (colon) to access value of new or old reference.

您需要使用':'(冒号)来访问新的或旧引用的值。