oracle 多表内连外连用法

oracle中join on 多表外连，内连，外连
比如


select * from A a left join B b on a.xxxx=b.xxx left join C c on a.xxxxxx=c.xxxxx left join D d on a.xxx=d.xx


select * from A a left outer join B b on a.xxxx=b.xxx left join C c on a.xxxxxx=c.xxxxx left join D d on a.xxx=d.xx