1、插入

    insert into dept values(50, ‘soft‘, ‘Guangzhou‘);

    insert into dept(deptno, dname) values(60, ‘software test‘);

    insert into dept select * from dept where deptno = 20;

2、删除

    delete from dept where deptno = 20;

    delete from dept;

3、修改

    update dept set dname = dname || ‘ ^.^‘ where deptno = 20;

4、事务

    每个修改语句完成后都可以回滚或提交，即rollback、commit；

    eg:

    insert into dept values(50, ‘soft‘, ‘Guangzhou‘);

    rollback;

    这样就回滚了，等于上面的没有插入；如果commit就提交了，此后如果再rollback也无力回天了。

    下面这样也是无法回滚的：

    insert into dept values(50, ‘soft‘, ‘Guangzhou‘);

    create table temp as select * from dept;

    rollback;

    再次查询，发现无法回滚；同样增删改后面运行grant/create语句也是无法回滚的；