Sql Server 01:随笔 sql初级操作

—基本增删改查
–创建表

create table student(
sid varchar(12) primary key,
sname varchar(5) not null,
sage int,
ssex char(2) check  (ssex='男'or ssex='女'),
sdate date,
length float
);

create table student(
sid varchar(12) primary key,
sname varchar(5) not null,
sage int,
ssex char(2) check (ssex='男’or ssex=‘女’),
sdate date,
length float
);

​—修改表名–不建议修改，更改对象名的任一部分都可能会破坏脚本和存储过程

EXEC sp_rename @objname='stu',@newname='student';
EXEC sp_rename  student,stu;

​–增加列

ALTER table student add smajor char(10);

–插入数据

insert   into student values('1821024','cjr',21,'男','2018-09-01',170.0,'信管');
insert into student(sid,sname,ssex,smajor)values('1821020','cyx','男','计算机');
!

采用命令

select* from student；

​–显示全部数据–不建议使用

select * from student;

–修改列名–不建议修改

EXEC sp_rename 'student.smajor', 'sdomain', 'column';

​–更新数据

update student set sdomain='英语' where sdomain='计算机';
select * from student ;

​–删除某一行

delete from student where sdomain='英语';

​

​–删除一列数据

alter table student drop column sdate;
​select * from student;

–删除表

drop table student;

​