表Student(Sid,Sname,Sage,Ssex) 学生表 CREATE TABLE student ( sid varchar(10) NOT NULL, sName varchar(20) DEFAULT NULL, sAge datetime DEFAULT '1980-10-12 23:12:36', sSex varchar(10) DEFAULT NULL, PRIMARY KEY (sid)) ENGINE=InnoDB DEFAULT CHARSET=utf8;Course(Cid,Cname,Tid) 课程表 CREATE TABLE course ( cid varchar(10) NOT NULL, cName varchar(10) DEFAULT NULL, tid int(20) DEFAULT NULL, PRIMARY KEY (cid)) ENGINE=InnoDB DEFAULT CHARSET=utf8;SC(Sid,Cid,score) 成绩表 CREATE TABLE sc ( sid varchar(10) DEFAULT NULL, cid varchar(10) DEFAULT NULL, score int(10) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8;Teacher(Tid,Tname) 教师表 CREATE TABLE taacher ( tid int(10) DEFAULT NULL, tName varchar(10) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8;数据：（MySQL）insert into taacher(tid,tName) values (1,'李老师'),(2,'何以琛'),(3,'叶平');insert into student(sid,sName,sAge,sSex) values ('1001','张三丰','1980-10-12 23:12:36','男'),('1002','张无极','1995-10-12 23:12:36','男'),('1003','李奎','1992-10-12 23:12:36','女'),('1004','李元宝','1980-10-12 23:12:36','女'),('1005','李世明','1981-10-12 23:12:36','男'),('1006','赵六','1986-10-12 23:12:36','男'),('1007','田七','1981-10-12 23:12:36','女');insert into sc(sid,cid,score) values ('1','001',80),('1','002',60),('1','003',75),('2','001',85),('2','002',70),('3','004',100),('3','001',90),('3','002',55),('4','002',65),('4','003',60);insert into course(cid,cName,tid) values ('001','企业管理',3),('002','马克思',3),('003','UML',2),('004','数据库',1),('005','英语',1);问题： 1、查询“001”课程比“002”课程成绩高旳所有学生旳学号; select a.Sid from (select sid,score from SC where Cid='001') a,(select sid,score from SC where Cid='002') b where a.score>b.score and a.sid=b.sid; 2、查询平均成绩不不大于 60 分旳同学旳学号和平均成绩; select Sid,avg(score) from sc group by Sid having avg(score) >60; 3、查询所...
