1、创建测试表,如下图。
create table test_col_1(id number, var varchar2(200));
create table test_col_2(id number, var varchar2(200));
2、插入测试数据,如下图。
insert into test_col_1
select level*8, 'var'||level*8 from dual connect by level <= 20;
insert into test_col_2
select level, 'var'||level from dual connect by level <= 100;
3、查询A表与B表关联记录,如下图。
select *
from test_col_2 b
where exists (select 1 from test_col_1 a where b.id = a.id)
4、查询A表全部数据及A、B有关联的数据,如下图。
select *
from test_col_1 a
union all
select *
from test_col_2 b
where exists (select 1 from test_col_1 a where b.id = a.id)