SQL 创建学生作业表 work

CREATE TABLE work ( cno nvarchar(20) NOT NULL, sno int NOT NULL, swork1 tinyint NOT NULL CHECK (swork1 >= 0 AND swork1 <= 100), swork2 tinyint NOT NULL CHECK (swork2 >= 0 AND swork2 <= 100), swork3 tinyint NOT NULL CHECK (swork3 >= 0 AND swork3 <= 100), PRIMARY KEY (cno, sno), FOREIGN KEY (cno) REFERENCES 课程表(课程号), FOREIGN KEY (sno) REFERENCES 学生表(学号) );