insert语句基本语法
insert into table(column) values(values);
insert into dept(deptno,dname,loc) values(50,'development','detroit'); //当所有列都要插入数值时可不写第二行,直接按照顺序写第三行
update语句
update dept set deptno=11 where loc='zjk';
delete语句
delete (from) dept where deptno=11;
commit 提交
ROLLBACK 回滚
savepoint 使用savepoint语句在当前事务中产生一个标记,使用rollback to 回滚到那个标记
savepoint a;
rollback to a;
从一个表中拷贝一行:
insert into t_emp(empno,ename,sal,hiredate) 不用写values,列与列之间应对应
select empno,ename,sal,hiredate from emp where job='MANAGER';
创建和管理表:
create table emp(id number(2),name varchar2(11),sal number(5)) ;
创建一个和emp一样的表
create table emp1 as select * from emp;
创建表,并将emp表按工资分成三个表
create table t_smallsal as select ename, empno, sal from emp where 1=2;create table t_middlelsal as select ename, empno, sal from emp where 1=2;create table t_largesal as select ename, empno, sal from emp where 1=2;insert allwhen sal < 1200 theninto t_smallsalwhen sal >=1200 and sal < 3000 theninto t_middlesalelse into t_largesal select ename, empno, sal from emp;
update t_employee t set t.sal = (select t1.sal from emp t1 where t1.empno = t.empno and t.sal != t1.sal) 利用子查询更新数据 where t.deptno = 20;
truncate 截断表 移除表中数据,释放存储空间 不可回退
truncate table emp;