标签：contents varchar join teacher connect toe c# 扩展 news
数据定义DDL
create alter drop truncate
数据操纵DML
insert select delete update
事务控制TCL
commit savepoint rollback
数据控制DCL
grant revoke
cmd连接数据库
sqlplus system/123@ORCLEHELLO1
查看所在库 select name from v$database
sys超级用户
system管理员
scott/tigrt测试用户
若scott/tigher用户被锁=====
conn sys/123456 as sysdba;
alter user scott account unlock; //解锁
conn scott/tigher //弹出一个修改密码的对话框,修改密码
修改sys/system用户密码=====
进入sqlplus 进行密码重置
sqlplus/as sysdba
空
alter user sys indentified by newpassword;
conn sys/newpassword as sysdba;
//用sys帐号更改system帐号密码
alter user system identified by newpassword;
conn system/newpassword
导出
exp username/password file="src.dmp"
导入
imp username/password file="src.dmp"
创建表空间 表名
create tablespace news datafile ‘D:\oradata\0\01.dbf‘ size 50m;
删除表空间
drop tablespace news;
查看表空间
select * from v$tablespace;
查看扩展信息
select tablespace_name,autoextensible from dba_data_files;
自增长 edit
alter database datafile ‘src‘ autoextend on;
添加文件
alter tablespace news
add datafile ‘D:\oradata\0\02.dbf‘ size 50m;
删除表空间和文件
drop tablespace news including contents and datafiles;
创建用户
create user c##thie identified by thie default tablespace news;
授权
grant connect,resource to c##thie;
对表空间授权
grant unlimited tablespace to c##thie;
char 固定长度字符
varchar2 可变长度字符
number 整数,浮点
number(3,1) 99.1 number(3) 999 number 无限制
date 日期
blob 二进制对象
clob 字符格式的大型对象
bfile 将二进制数据存储操作系统文件中
新建表
create table teacher //教师表
(tno number(4) not null, //教师编号4 不能为空
tname varchar2(14) not null, //教师名字 字符14 不能为空
tid char(18), //身份证号 字符18
gender char(2), //性别 字符2
birthdate date) //生日 日期
/
增加列
alter table teacher add(
sal number(7,2),hirdate date,wechat varchar2(30));
查看表
desc teacher;
修改列名
alter table teacher rename column 要改的列名 to 新列名;
改
alter table teacher modify(tname varchar2(30));
删
alter table teacher drop column wechat;
添加约束
主键(列数据唯一 不能为空)(primary key)
alter table teacher add constraint pk_teacher primary key(tno);
唯一(列数据唯一 允许为空 只能一个空值)(unique)
alter table teacher add constraint uk_teacher_tname unique(tname);
检查(限制取值范围)(check)
alter table teacher add constraint ck_teacher_gender check(gender in(‘男‘,‘女‘));
外键(关联表)(foreign key)
alter table teacher add constraint fk_teacher_deptno_dept foreign key(deptno) references dept(deptno);
删除约束
alter table dept
drop constraint deptno;
不重复distinct
select distinct deptno from teacher where deptno is not null
插入
insert into teacher (tno,tname,tid,gender) values(1,‘11‘,‘111‘,‘男‘)
commit;
查看表
select * from teacher;
删除
delete from teacher;
commit;
创建序列
create sequence sq_teacher
start with n increment by 1;
初始化序列
select sq_teacher.nextval from dual;
当前序列
select sq_teacher.currval from dual;
修改列为10
update teacher set deptno=10;
指定修改目标
update teacher set sal=sal+2000 where
tname in(‘陈老师‘,‘韩老师‘);
删除所有姓蔣的老师
delete from teacher where tname like ‘蒋%‘;
删除所有教师和部门
delete from teacher;
delete from dept;
回退
rollback;
截断
truncate table teacher;
select * from teacher t where t.job=‘研发‘ or t.job=‘讲师‘ order by t.sal desc
select ‘insert into dept values(‘||deptno||‘,‘||dname||‘,‘||loc||‘)‘ from dept
select ‘insert into dept values(‘||deptno||‘,‘‘‘||dname||‘‘‘,‘‘‘||loc||‘‘‘)‘ from dept
select * from TEACHER t where sal between 10000 and 20000
select t.tname,t.deptno,(select dname from dept where dept.deptno=t.deptno)as deptname from teacher t
select t.tname,t.deptno,(select dname from dept where deptno = t.deptno) from teacher t where t.deptno in(select deptno from dept where t.deptno=deptno and dname in(‘人力部‘,‘招生部‘))
select tname,(select dname from dept where deptno=t.deptno) from TEACHER t where deptno in(select deptno from dept where dname=‘招生部‘) and gender=‘男‘
select tname,teacher.deptno,dept.dname from teacher inner join dept on teacher.deptno=dept.deptno where dept.dname=‘招生部‘ and gender=‘男‘
select tname,dname,dept.deptno from teacher inner join dept on dept.deptno=teacher.deptno
select t1.tno,t1.tname,t1.mgrno,t2.tname from teacher t1 left join teacher t2 on t1.mgrno=t2.tno
select t1.tno,t1.tname,dept.dname as 部门,t2.tname as 导师 from teacher t1 left join teacher t2 on t1.mgrno=t2.tno left join dept on dept.deptno=t1.deptno
select round(sal,-1 ) from teacher
select sysdate+1/24 from dual
select to_number(‘112‘), to_char(1122), to_date(‘1986-1-3‘,‘yyyy-mm-dd‘)from dual
select to_char(sysdate,‘yyyy-mm-dd hh24-mi-ss‘) from dual
select sal,comm,(sal+nvl(comm,0))as 总和 from teacher
select sal,comm,(sal+nvl(comm,0))as 总和,(sal+nvl2(comm,comm+1000,0))as 总和 from teacher
select sal,comm,(sal+nvl(comm,0))as 总和,(sal+nvl2(comm,comm+1000,0))as 总和,decode(comm,null,0,2300,2600,0) from teacher
select deptno,sum(sal),avg(sal),count(0),max(sal),min(sal) from teacher group by deptno having count(*)>10
select tname,deptno,sal,
rank() over(partition by deptno order by sal desc) rank,
dense_rank() over(partition by deptno order by sal desc) dense_rank,
row_number() over(partition by deptno order by sal desc) row_number from teacher
select * from (select rownum as rn,tname from teacher where rownum<=10) t where t.rn>=5
select * from (select e.*,rownum rn from (select * from teacher order by sal desc) e where rownum<=9) where rn >=5
各部门最高工资的人员
select t.tname,t.sal,t.deptno,(select dname from dept where dept.deptno=t.deptno)as 部门 from teacher t join (select max(sal) maxsal,deptno from teacher group by deptno) d
on(t.sal=d.maxsal and t.deptno=d.deptno)
返回boolean判断是否存在exists
select t.tname,t.deptno from teacher t
where exists (select ‘a‘ from dept where dept.deptno=t.deptno)
标签：contents varchar join teacher connect toe c# 扩展 news
原文地址：http://www.cnblogs.com/m97i/p/6915944.html
