mysql on和where,连接汇总

感觉sql很垃圾，连接忘完了，整理一下
连接分为left join,right join,和join吧
join就是inner join
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jon 条件放在on或者where后面一样，没啥区别，不过滤 left join和right join 把条件放在on和where后面，有区别

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eg:

CREATE TABLE `product` (
  `id` int(10) unsigned NOT NULL auto_increment,
  `amount` int(10) unsigned default NULL,
  PRIMARY KEY  (`id`)
)  CHARSET=latin1
 
CREATE TABLE `product_details` (
  `id` int(10) unsigned NOT NULL,
  `weight` int(10) unsigned default NULL,
  `exist` int(10) unsigned default NULL,
  PRIMARY KEY  (`id`)
) CHARSET=latin1
 
INSERT INTO product (id,amount)
       VALUES (1,100),(2,200),(3,300),(4,400);
 
INSERT INTO product_details (id,weight,exist)
       VALUES (2,22,0),(4,44,1),(5,55,0),(6,66,1);

//这个是正常的，不用连接得sql，条件放到where后面
select * from product a , product_details b  where a.id=b.id and a.id!=2 and b.id!=2; 

select * from product a inner join product_details b  on a.id=b.id and a.id!=2 and b.id!=2;
select * from product a inner join product_details b  on a.id=b.id where a.id!=2 and b.id!=2;

left join

select * from product_details a left join product b on a.id=b.id; 
select * from product_details a left join product b on a.id=b.id and a.id=2; 
select * from product_details a left join product b on a.id=b.id where a.id=2; 

right join

select * from product_details a right join product b on a.id=b.id; 
select * from product_details a right join product b on a.id=b.id and a.id=2; 
select * from product_details a right join product b on a.id=b.id where a.id=2; 

select * from product_details a right join product b on a.id=b.id where a.id!=2;