create table a (a varchar(100), b varchar(100)); create table b (a varchar(100), b varchar(100)); insert into a values ('1','a'); insert into a values ('2','b'); insert into a values ('3','c'); insert into b values ('2','e'); insert into b values ('3','f'); select a.a,a.b,b.b as bb from a,b where a.a=b.a(+)--就这句 drop table a; drop table b;
SELECT a.*,b.* FROM a LEFT OUTER JOIN b WHERE a.user_name=b.user_name
(a varchar(100),
b varchar(100));
create table b
(a varchar(100),
b varchar(100));
insert into a values ('1','a');
insert into a values ('2','b');
insert into a values ('3','c');
insert into b values ('2','e');
insert into b values ('3','f');
select a.a,a.b,b.b as bb from a,b where a.a=b.a(+)--就这句
drop table a;
drop table b;
from ( select a || b ab from B) B,A
where B.ab = a.a(+)
select *
from ( select a || b ab from B) B
,( select distinct * from A) A
where B.ab = A.a(+)