--insert into添加数据
insert into student(sno,sname,ssex) values(‘110‘,‘王军‘,‘男‘);


--提交事物
commit;

--回滚事物
--rollback;

insert into teacher1 select * from teacher;
insert into teacher1(ton,tname,prof) select ton,tname,prof from teacher;


--选择性插入两表之间
insert into teacher1 t(ton,tname,prof) select ton,tname,prof from teacher where ton=‘804‘;


--修改 update
update student set sclass=‘95031‘，ssex=‘女‘ where son=‘104‘;
commit


--修改成绩
update score set degree=degree+1;


--将空sclass内容更改95033
update student set sclass=‘95033‘ where sclass is null; 


--删除 delete
delete from student where sno=‘104‘;


--全表快速清空：先删表，在建表
truncate table stdent;