mysql學習 表內連線查詢

查詢兩個表中符合條件的共有記錄

內連線查詢效果圖:

內連線查詢語法格式:

select 字段 from 表1 inner join 表2 on 表1.欄位1 = 表2.欄位2；

在這裡我們先建立三個表分別是：student學生表，course課程表，stu_cour選課表

create table student(

id int unsigned primary key auto_increment not null, 
name varchar(20) not null comment '學生姓名'
);insert into student values(0,'諸葛亮'),(0,'虞姬'),(0,'孫尚香'),(0,'趙雲'),(0,'宮本武藏');
create table course(
id int unsigned primary key auto_increment not null, 
name varchar(20) not null comment '課程名稱'
);insert into course values
(0,'語文'),
(0,'數學'),
(0,'英語'),
(0,'物理'),
(0,'化學'),
(0,'歷史'),
(0,'地理');
create table stu_cour(
stu_id int comment '學生id',
cour_id int comment '課程id',
primary key(stu_id,cour_id)
);insert into stu_cour values
(1,1),(1,2),(1,3),(1,4),
(2,1),(2,2),(2,3),(2,5),
(3,1),(3,2),(3,3),(3,7),
(4,1),(4,2),(4,3),(4,4),
(5,1),(5,2),(5,3),(5,5);

select * from student as s inner join stu_cour as sc inner join course as c on s.id=sc.stu_id and sc.cour_id=c.id and s.name='諸葛亮';

select * from student as s inner join stu_cour as sc inner join course as c on s.id=sc.stu_id and sc.cour_id=c.id and c.name='物理';

select c.name from stu_cour as sc inner join course as c on sc.cour_id=c.id group by c.name;

select name from course where name not in (select c.name from stu_cour as sc inner join course as c on sc.cour_id=c.id group by c.name);

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