select * from xxaa a,xxbb b where a.id(+)=b.idd;--右连接，以B表为基表，匹配B表中的都输出
select * from xxaa a,xxbb b where a.id=b.idd(+); --左连接，以A表为基表，匹配A表的都输出 相当于left join 和left outer Join
select * from xxaa a,xxbb b where a.id=b.idd; -- =连接 A,B表都匹配才输出
select * from xxaa a left join xxbb b on (a.id=b.idd); --左内连
select * from xxaa a right join xxbb b on (a.id=b.idd); --右内连
select * from xxaa a full join xxbb b on (a.id=b.idd); --完全连接 --A表和B表的 并集
select * from xxaa a inner join xxbb b on (a.id=b.idd); --内连接 --A表和B表的 交集
select * from xxaa a left outer join xxbb b on (a.id=b.idd);--左外连
select * from xxaa a right outer join xxbb b on (a.id=b.idd); --右外连
select * from xxaa a full outer join xxbb b on (a.id=b.idd); --完全外联
select * from xxaa a join xxbb b on (a.id=b.idd); --相当于= 连接