5、外联查询

1、左联
left join
a.name = b.name(+)
temp1:  select * from table_a a left join table_b b on a.name=b.name;
temp2;  select * from table_a a ,test_b b where a.store_name=b.store_name(+)

2、内链
inner join
a.name = b.name
temp:  参看左联

3、右联
right join
a.name(+) =b.name
temp:  参看左联