1）根据表查询平均成绩大于等于 60 分的同学的学生编号...

1）根据表查询平均成绩大于等于 60 分的同学的学生编号和学生姓名和平均成绩 2）根据表查询在 SC 表存在成绩的学生信息 实验数据： 学生表： create table Student(Sid varchar(6), Sname varchar(10), Sage datetime, Ssex varchar(10)); insert into Student values('01' , '赵雷' , '1990-01-01' , '男'); insert into Student values('02' , '钱电' , '1990-12-21' , '男'); insert into Student values('03' , '孙风' , '1990-05-20' , '男'); insert into Student values('04' , '李云' , '1990-08-06' , '男'); insert into Student values('05' , '周梅' , '1991-12-01' , '女'); insert into Student values('06' , '吴兰' , '1992-03-01' , '女'); insert into Student values('07' , '郑竹' , '1989-07-01' , '女'); insert into Student values('08' , '王菊' , '1990-01-20' , '女') 成绩表 create table SC(Sid varchar(10), Cid varchar(10), score decimal(18,1)); insert into SC values('01' , '01' , 80); insert into SC values('01' , '02' , 90); insert into SC values('01' , '03' , 99); insert into SC values('02' , '01' , 70); insert into SC values('02' , '02' , 60); insert into SC values('02' , '03' , 80); insert into SC values('03' , '01' , 80); insert into SC values('03' , '02' , 80); insert into SC values('03' , '03' , 80); insert into SC values('04' , '01' , 50); insert into SC values('04' , '02' , 30); insert into SC values('04' , '03' , 20); insert into SC values('05' , '01' , 76); insert into SC values('05' , '02' , 87); insert into SC values('06' , '01' , 31); insert into SC values('06' , '03' , 34); insert into SC values('07' , '02' , 89); insert into SC values('07' , '03' , 98) 课程表 create table Course(Cid varchar(10), Cname varchar(10), Tid varchar(10)); insert into Course values ('01' , '语文' , '02'); insert into Course values ('02' , '数学' , '01'); insert into Course values ('03' , '英语' , '03') 教师表 create table Teacher(Tid varchar(10), Tname varchar(10)); insert into Teacher values ('01' , '张三'); insert into Teacher values ('02' , '李四'); insert into Teacher values ('03' , '王五')