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 select s_country_id.nextval into :new.country_id from dual; end; /
请问一下 select s_country_id.nextval into :new.country_id from dual; 中的new.country_id是什么意思?
country_id是表中字增的字段, select s_country_id.nextval into :new.country_id from dual; 这个sql就是从序列中取出字增数据放到那个字段下
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
select s_country_id.nextval into :new.country_id from dual;
end;
/
select s_country_id.nextval into :new.country_id from dual;
这个sql就是从序列中取出字增数据放到那个字段下