我尝试使用以下代码创建触发器。
CREATE OR REPLACE TRIGGER MYTABLE_TRG
BEFORE INSERT ON MYTABLE
FOR EACH ROW
BEGIN
select MYTABLE_SEQ.nextval into :new.id from dual;
END;
我收到了错误
Error(2,52): PLS-00049: bad bind variable 'NEW.ID'
有任何想法吗?谢谢。
似乎错误代码告诉你表中没有这样的列ID ...
不知何故,您的环境将您的代码视为SQL而不是DDL语句。这对我有用(从命令提示符下运行sqlplus.exe):
SQL> create sequence mytable_seq;
Sequence created.
SQL> create table mytable (id number);
Table created.
SQL> CREATE OR REPLACE TRIGGER MYTABLE_TRG
2 BEFORE INSERT ON MYTABLE
3 FOR EACH ROW
4 BEGIN
5 select MYTABLE_SEQ.nextval into :new.id from dual;
6 END;
7 /
Trigger created.
请注意尾部的“/” - 这可能在您正在编译它的应用程序中很重要。
如果一个人会使用正确的命名约定,这种类型的错误的发现将更容易(对于使用前缀和后缀的正确方法)通用对象名称暗示其目的更好,即这样的事情会发现correct答案
--START -- CREATE A SEQUENCE
/*
create table "TBL_NAME" (
"TBL_NAME_ID" number(19,0) NOT NULL
, ...
*/
--------------------------------------------------------
-- drop the sequence if it exists
-- select * from user_sequences ;
--------------------------------------------------------
declare
c int;
begin
select count(*) into c from user_sequences
where SEQUENCE_NAME = upper('SEQ_TBL_NAME');
if c = 1 then
execute immediate 'DROP SEQUENCE SEQ_TBL_NAME';
end if;
end;
/
CREATE SEQUENCE "SEQ_TBL_NAME"
MINVALUE 1 MAXVALUE 999999999999999999999999999
INCREMENT BY 1 START WITH 1
CACHE 20 NOORDER NOCYCLE ;
-- CREATE
CREATE OR REPLACE TRIGGER "TRG_TBL_NAME"
BEFORE INSERT
ON "TBL_NAME"
REFERENCING NEW AS New OLD AS Old
FOR EACH ROW
DECLARE
tmpVar NUMBER;
BEGIN
tmpVar := 1 ;
SELECT SEQ_TBL_NAME.NEXTVAL INTO tmpVar FROM dual;
:NEW.TBL_NAME_ID := tmpVar;
END TRG_TBL_NAME;
/
ALTER TRIGGER "TRG_TBL_NAME" ENABLE;
-- STOP -- CREATE THE TRIGGER