详解Mysql两表 join 查询方式

SELECT DISTINCT
	< select_list > 
FROM
	< left_table > < join_type >
JOIN < right_table > ON <join_condition>
WHERE
	< where_condition > 
GROUP BY
	< group_by_list > 
HAVING
	< having_condition > 
ORDER BY
	< order_by_condition > 
LIMIT < limit_number >

select A.*,B.* from A left join B on A.id = B.id;

select A.*,B.* from A right join B on A.id=B.id;

select A.*,B.* from A inner join B on A.id=B.id;

select A.*,B.* from A left join B on A.id=B.id where B.id is null;

select A.*,B.* from A right join B on A.id=B.id where A.id is null;

select A.*,B.* from A left join B on A.id=B.id where B.id is null
union
select A.*,B.* from A right join B on A.id=B.id where A.id is null;

select A.*,B.* from A left join B on A.id=B.id
UNION
select A.*,B.* from A right join B on A.id=B.id;