MySQL 的七种 Join

Posted 2021-01-01 tkzl

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创建表

学生表

create table student(  
  id int(11) not null AUTO_INCREMENT,
  name varchar(30),
  address varchar(40),
  primary key (id)
) engine=innodb charset=utf8;

INSERT INTO student(name,address) VALUES(‘田开智‘,‘安徽省天长市‘);
INSERT INTO student(name,address) VALUES(‘陶沪生‘,‘安徽省铜陵市‘);
INSERT INTO student(name,address) VALUES(‘石冬冬‘,‘安徽省安庆市‘);
INSERT INTO student(name,address) VALUES(‘魏忠原‘,‘安徽省滁州市‘);
INSERT INTO student(name,address) VALUES(‘田永恒‘,‘安徽省阜阳市‘);
INSERT INTO student(name,address) VALUES(‘熊发挥‘,‘安徽省天长市‘);

成绩表

create table chengji(  
  id int(11) not null AUTO_INCREMENT,
  socre float(5,2),
  primary key (`id`)
) engine=innodb charset=utf8;

INSERT INTO chengji(socre) VALUES(95.54);
INSERT INTO chengji(socre) VALUES(124.4);
INSERT INTO chengji(socre) VALUES(130.0);
INSERT INTO chengji(socre) VALUES(135);
INSERT INTO chengji(socre) VALUES(149.547);

INSERT INTO chengji(id,socre) VALUES(7,140);