Oracle 创建表格

--创建一个用户create user gsq  identified by qq123; --分配权限grant connect ,resource to gsq;--收回权限revoke connet from gsq;

创建表格

create table student(  sno number primary key,  sname varchar2(30) not null,  sex char(2) default '男',  age int check(age>18 and age<=30),  enterDate date,  cno number,  email varchar2(100) unique,  foreign key (cno) references clazz(cno))--删除表drop table student;select * from student;insert into student values(1,'张三','男',22,sysdate,'1','2@com');insert into student values(2,'李四','女',19,sysdate,'2','3@com');insert into student values(3,'王五','男',20,sysdate,'3','4@com');--验证性别默认值insert into student(sno,sname,age,enterdate,cno) values (4,'小红',30,sysdate,4);--修改表 添加一列alter table student add addr varchar2(200);--修改一列alter table student modify addr varchar2(300);--删除一列alter table student drop column addr;--创建班级表create table clazz(  cno number primary key,  cname varchar2(50),  chead varchar2(20))--删除表格drop table clazz;--表格中插入数据insert into clazz values(1,'1班','王老师');insert into clazz values(2,'2班','陆老师');insert into clazz values(3,'3班','范老师');insert into clazz values(4,'3班','范老师');--修改表格中的内容update clazz set cname='sxt三班' where cname = '3班';select * from clazz;