create database 你的名字(NAME='你的名字', MAXSIZE=10MB, FILEGROWTH=10%);create table student(学号 char(10) primary key, 姓名 char(10) not null, 性别 char(4) default '男', 年龄 int, 系别 char(20) not null)create table course(课程号 char(10) primary key, 课程名 char(20) not null, 学分 smallint not null)create table sc(学号 char(10) not null, 课程号 char(10) not null, 成绩 int not null, foreign key (学号) references student(学号), foreign key (课程号) references course(课程号))insert into student values('1','李明','男',20,'计算机系');insert into student values('2','张然','女',19,'经管系');insert into student values('3','许晴','女',18,'电子系');insert into course values('1','SQL Server',4);insert into course values('2','VB',3);insert into course values('3','专业英语',2);insert into sc values('1','1',90);insert into sc values('2','1',85);insert into sc values('2','2',76);insert into sc values('3','3',70);select *from studentwhere 年龄>18order by 学号 DESC