MySQL left join right join inner join 区别

请看下面的语句

注意比较06 和07的显示结果，自己测试的 语法没有错误

-- left join , right join ,inner join 实验

CREATE DATABASE if NOT EXISTS join_test;

use join_test;

DROP TABLE If EXISTS tbl_a;

create table tbl_a (

id int(11) auto_increment primary key,

name varchar(255),

email varchar(255)

);

DROP TABLE If EXISTS `tbl_b`;

create table `tbl_b`(

`id` int(11) auto_increment primary key,

`name` varchar(255),

`email` varchar(255)

);

use join_test;

-- inset into tbl_a

insert into tbl_a values(1,'a_name_001','a_email_001');

insert into tbl_a values(2,'a_name_002','a_email_002');

insert into tbl_a values(3,'a_name_003','a_email_003');

insert into tbl_a values(4,'a_name_004','a_email_004');

insert into tbl_a values(5,'a_name_005','a_email_005');

insert into tbl_a values(7,'a_name_007','a_email_007');

-- insert into tbl_b

insert into tbl_b values(1,'b_name_001','b_email_001');

insert into tbl_b values(2,'b_name_002','b_email_002');

insert into tbl_b values(3,'b_name_003','b_email_003');

insert into tbl_b values(4,'b_name_004','b_email_004');

insert into tbl_b values(5,'b_name_005','b_email_005');

insert into tbl_b values(6,'b_name_006','b_email_006');

-- left join

select * from tbl_a left join tbl_b on tbl_a.id=tbl_b.id;

查询结果：

-- right join

select * from tbl_a right join tbl_b on tbl_a.id=tbl_b.id;

查询结果：

-- inner join

select * from tbl_a inner join tbl_b on tbl_a.id=tbl_b.id

查询结果：