序列和触发器

建立序列后，还需要触发器，在插入的时候，新增自增

create sequence "seq_unit"
 increment by 1 
start with 1 
minvalue 1 
maxvalue 999
 cycle 
nocache 
order;

CREATE OR REPLACE TRIGGER "TRI_UNIT_BEFORE_INSERT" BEFORE
       INSERT ON TBL_UNIT FOR EACH ROW 
BEGIN
       SELECT SEQ_UNIT.NEXTVAL INTO :NEW.UNIT_ID FROM DUAL;
END;