--删除表

--drop table teachers;

--创建表

create table teachers

(

tno varchar2(6) not null,

tname varchar2(8) not null,

tsex varchar2(4) not null,

tsr date,

pro varchar2(10),

depa varchar2(14)

);

--添加注释

comment on column teachers.tno

is' 教师编号（主键）';

comment on column teachers.tname

is' 教师名称';

comment on column teachers.tsex

is' 教师性别）';

comment on column teachers.tsr

is' 教师生日';

comment on column teachers.pro

is' 教师职称）';

comment on column teachers.depa

is' 教师部门）';

--添加主键约束

--alter 修改的意思

alter table teachers add constraint pk_teachers primary key(tno);