mysql 7 種 join
阿新 • • 發佈：2018-04-26
AS mys from null com union http nio where
一、
select * from A inner join B on A.key = B.key
二、
select * from A left join B on A.key = B.key
三、
select * from A right join B on A.key = B.key
四、
select * from A left join B on A.key = B.key where b.key is null
五、
select * from A right join B on A.key = B.key where A.key is null
六、
select * from A left join B on A.key = B.key union select * from A right join B on A.key = B.key
七、
select * from A left join B on A.key = B.key where B.key is null union select * from A right join B on A.key = B.key where A.key is null
mysql 7 種 join