CREATE TABLE STUDENT(ID INT NOT NULL,NAME VARCHAR2(4000) NOT NULL,PRIMARY KEY(ID))TABLESPACE MYDB; --创建自增ID，名称为：表名_字段名_SEQCREATE SEQUENCE sTUDENT_ID_SEQ MINVALUE 1 NOMAXVALUE INCREMENT BY 1 START WITH 1 NOCACHE;  -- 为Insert操作创建触发器，无需在SQL语句里写NEXTVAL，名称为表名_INS_TRGCREATE OR REPLACE TRIGGER sTUDENT_INS_TRG BEFORE INSERT ON STUDENT FOR EACH ROW WHEN(NEW.ID IS NULL)BEGINSELECT STUDENT_ID_SEQ.NEXTVAL INTO :NEW.ID FROM DUAL;END;