附上數據准備：
學生表
create table Student(SId varchar(10),Sname varchar(10),Sage datetime,Ssex varchar(10)); insert into Student values('01' , '趙雷' , '1990-01-01' , '男'); insert into Student values('02' , '錢電' , '1990-12-21' , '男'); insert into Student values('03' , '孫風' , '1990-12-20' , '男'); insert into Student values('04' , '李雲' , '1990-12-06' , '男'); insert into Student values('05' , '周梅' , '1991-12-01' , '女'); insert into Student values('06' , '吳蘭' , '1992-01-01' , '女'); insert into Student values('07' , '鄭竹' , '1989-01-01' , '女'); insert into Student values('09' , '張三' , '2017-12-20' , '女'); insert into Student values('10' , '李四' , '2017-12-25' , '女'); insert into Student values('11' , '李四' , '2012-06-06' , '女'); insert into Student values('12' , '趙六' , '2013-06-13' , '女'); insert into Student values('13' , '孫七' , '2014-06-01' , '女');
科目表 Course
create table Course(CId varchar(10),Cname nvarchar(10),TId varchar(10)); insert into Course values('01' , '語文' , '02'); insert into Course values('02' , '數學' , '01'); insert into Course values('03' , '英語' , '03');
教師表 Teacher
create table Teacher(TId varchar(10),Tname varchar(10)); insert into Teacher values('01' , '張三'); insert into Teacher values('02' , '李四'); insert into Teacher values('03' , '王五');
成績表 SC
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);
練習工具：navicat for mysql