小菜菜mysql练习50题解析——数据准备

附上数据准备：

学生表

create table student(sid varchar(10),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' , '1990-12-20' , '男');
insert into student values('04' , '李云' , '1990-12-06' , '男');
insert into student values('05' , '周梅' , '1991-12-01' , '女');
insert into student values('06' , '吴兰' , '1992-01-01' , '女');
insert into student values('07' , '郑竹' , '1989-01-01' , '女');
insert into student values('09' , '张三' , '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' , '赵六' , '2013-06-13' , '女');
insert into student values('13' , '孙七' , '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' , '语文' , '02');
insert into course values('02' , '数学' , '01');
insert into course values('03' , '英语' , '03');

教师表 teacher

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');

成绩表 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);

练习工具：navicat for mysql