3、使用SQL语句完成创建学生表student并添加五条测试语句字段如下 字段名称 数据类型 约束学生编号 Stuid int 主键自增学生名称 StuName Varchar50 非空约束学生性别 StuGender Vahrcar2 默认约束 ‘男’学生年龄 StuAge Int2 检查约束学生邮箱 StuEmail Varchar50 唯一约束 注意：使用SQL语句添加外键约束时需

1、创建学生表student：

CREATE TABLE student ( Stuid INT PRIMARY KEY AUTO_INCREMENT, StuName VARCHAR(50) NOT NULL, StuGender VARCHAR(2) DEFAULT '男', StuAge INT(2) CHECK (StuAge >= 0), StuEmail VARCHAR(50) UNIQUE );

2、添加五条测试语句：

INSERT INTO student (StuName, StuGender, StuAge, StuEmail) VALUES ('张三', '男', 20, 'zhangsan@example.com'); INSERT INTO student (StuName, StuGender, StuAge, StuEmail) VALUES ('李四', '女', 19, 'lisi@example.com'); INSERT INTO student (StuName, StuGender, StuAge, StuEmail) VALUES ('王五', '男', 21, 'wangwu@example.com'); INSERT INTO student (StuName, StuGender, StuAge, StuEmail) VALUES ('赵六', '女', 18, 'zhaoliu@example.com'); INSERT INTO student (StuName, StuGender, StuAge, StuEmail) VALUES ('钱七', '男', 22, 'qianqi@example.com');

3、创建课程表course：

CREATE TABLE course ( CourseId INT PRIMARY KEY AUTO_INCREMENT, CourseName VARCHAR(50) NOT NULL );

4、添加三条测试语句：

INSERT INTO course (CourseName) VALUES ('数学'); INSERT INTO course (CourseName) VALUES ('英语'); INSERT INTO course (CourseName) VALUES ('物理');

5、创建学生和课程的中间表middle_table：

CREATE TABLE middle_table ( Stuid INT, CourseId INT, PRIMARY KEY (Stuid, CourseId), FOREIGN KEY (Stuid) REFERENCES student(Stuid) ON DELETE CASCADE, FOREIGN KEY (CourseId) REFERENCES course(CourseId) ON DELETE CASCADE )