怎么编写触发器？

[msgsnd]

我有一个表test，主键是个流水号test_id，现在要在程序里插入一行,怎么自动生成这个id？
请高手指教？

[yuxuan]

同意楼上

[black_snail]

Try this :

create or replace trigger trg_contnr_list
BEFORE INSERT
ON contnr_list
REFERENCING NEW AS NEW OLD AS OLD
FOR EACH ROW
declare
l_n_sq_number number(23);
Begin
select n_sq_cntnr_list.nextval into l_n_sq_number from dual;
:new.v_rowid := l_n_sq_number;
end;

[bzszp]

第一步：创建SEQUENCE
create sequence s_country_id increment by 1 start with 1 maxvalue 999999999;
第二步：创建一个基于该表的before insert 触发器，在触发器中使用该SEQUENCE
create or replace trigger bef_ins_t_country_define
before insert on t_country_define
referencing old as old new as new for each row
begin
new.country_id=s_country_id.nextval;
end;