-- Create table create table STUDENT ( sno VARCHAR2(3) not null, sname VARCHAR2(8) not null, ssex VARCHAR2(2) not null, sbirthday DATE, class VARCHAR2(5) ) tablespace USERS pctfree 10 initrans 1 maxtrans 255 storage ( initial 64K next 1M minextents 1 maxextents unlimited ); -- Add comments to the table comment on table STUDENT is '学生表'; -- Add comments to the columns comment on column STUDENT.sno is '学号(主键)'; comment on column STUDENT.sname is '学生姓名'; comment on column STUDENT.ssex is '学生性别'; comment on column STUDENT.sbirthday is '学生出生年月'; comment on column STUDENT.class is '学生所在班级';