MS SQL SERVER数据库简单回顾
MS SQL SERVER数据库
1.创建数据库
create database javateam;
2.使用数据库
use javateam;
3.创建表
create table 表名
(
字段名 字段类型 主键 字段增长(从X开始 , 每次加X个),
字段名 字段类型,
字段名 字段类型
);
create table peopleNone ( pid int primary key identity(1,1), pname varchar(32), psex varchar(32) );
4.查询表
--select * from peopleNone;
--select distinct pname,psex from peopleNone;
5.添加数据
insert into peopleNone(pname,psex) values('MR.MA','male'); insert into peopleNone(pname,psex) values('MR.LU','female');
6.删除表
(1)删除表,删除了表的结构
drop table peopleNone;
(2)清除表的数据,没有删除表结构
truncate table peopleNone;
(3)根据条件删除
delete from peopleNone where pname = 'MR.MA';
7.修改表
update peopleNone set pname = 'MR.LU',psex = 'male' where pid = 2;
8.添加约束
(1)语法:
alter table 表名
add constraint 约束名 foreign(外键) key references 主键表(主键)
alter table stu_info
add constraint fk_s foreign key(sid) references stu_table(sid);
(2)添加数据
insert into stu_table(sname,sclass)values('土豪zhang','2'); insert into stu_info(sid,sphone)values('2','12111');
(3)更新,更新的SID号需要在主键中存在
update stu_info set sphone = 8955 where sid = 1;
(4)删除,当主外键形成约束时,删除主键会异常,需要先删除外键
delete from stu_info where sid = 1;
(5)联合查询
select sname,sclass,sphone from stu_table s,stu_info b where b.sid = s.sid;
9.复合查询(子查询)
1.关键字:and or not
select count(*) as '记录条数' from ablum; select * from ablum where aid between 1 and 3; select * from ablum where not aid = 2;
2.模糊查询
语法:like a% %a% %a a_ (类似正则表达式)
select * from ablum where aname like '%f%';
3.其他
语法:最大最小 ,max min
select min(aid) as '最小值' from ablum;
语法:复合查询,规避。。排除前三
select * from ablum where aid not in
(select top 3 aid from ablum);
4.分页
语法:
select top(页面长度) * from 表名 where 主键 not in
(select top(页面长度 * (页码-1))主键 from 表名);
select top(4) * from ablum where aid not in (select top(4 * (2-1)) aid from ablum);