sequence怎么用

下面是oracle下建序号的代码:create sequence sequence_nameincrease by 1  --(这里1是增量,你可以设成别的数)start with 1000  --(初值)nomaxvaluenocyclenocache然后将序列插入表中:insert into table_name values(sequnce_name.nextval,column_name......);想实现自动增长只能用触发器:create or replace trigger trigger_namebefore insert on table_name for each rowbeginselect seqence_name.nextval into:new.column_name from dual;end trigger_name;