下面是两张桌子的图片，车主和车辆。
我需要找出拥有所有类型自行车的车主。
例子：
O_id 100,O_id 101,O_id 102 有 V_id=1 的自行车，但是
O_id 103 拥有所有类型的自行车（V_id = 1 和 V_id = 5）
如何编写查询来获取这些详细信息？
我的查询：
select o.o_id from owner o,vehicles v where
o.v_id = v.v_id where v_type = 'bike'
这是显示所有拥有自行车的车主，而不是拥有所有自行车的车主
【问题讨论】：
标签： sql database postgresql join subquery
这里有两个使用子查询和连接查询的查询：
架构：
drop table vehicle;
drop table owner;
create table vehicle(V_id int, V_type varchar(20));
create table owner(O_id int , V_id int);
insert into vehicle values(1,'Bike');
insert into vehicle values(2,'Car');
insert into vehicle values(3,'Car');
insert into vehicle values(4,'Car');
insert into vehicle values(5,'bike');
insert into owner values(100, 1);
insert into owner values(101, 1);
insert into owner values(102, 1);
insert into owner values(103, 1);
insert into owner values(100, 2);
insert into owner values(101, 3);
insert into owner values(103, 5);
子查询：
postgres=# select count(*) as bike_count, O_id from owner where V_id in (
postgres(# select V_id from vehicle where upper(V_type) = 'BIKE'
postgres(# )
postgres-# group by 2
postgres-# order by 1 desc
postgres-# ;
bike_count | o_id
------------+------
2 | 103
1 | 101
1 | 100
1 | 102
(4 rows)
加入查询：
postgres=# select count(*) as bike_count, O_id from owner o join vehicle v using(v_id)
postgres-# where upper(v.V_type) = 'BIKE'
postgres-# group by 2
postgres-# order by 1 desc
postgres-# ;
bike_count | o_id
------------+------
2 | 103
1 | 100
1 | 102
1 | 101
(4 rows)
如果您只需要所有者，可以将查询限制为 1 个
【讨论】：
with bykes as (
select array_agg(v_id) as byke_ids
from vehicle
where lower(v_type) = 'byke'
), owner as (
select o_id, array_agg(v_id) as v_ids
from owner
group by o_id
)
select o_id
from owner cross join bykes
where v_ids @> byke_ids
;
o_id
------
103
架构：
create table owner (
o_id int,
v_id int
);
create table vehicle (
v_id int,
v_type text
);
insert into owner (o_id, v_id) values
(100, 1),
(101, 1),
(102, 1),
(103, 1),
(100, 2),
(101, 3),
(103, 5);
insert into vehicle (v_id, v_type) values
(1, 'Byke'),
(2, 'Car'),
(3, 'Car'),
(4, 'Car'),
(5, 'byke');
【讨论】：
按您想要获取的o_id分组。
只取那些拥有相同数量 (count(v_id)) 的自行车组，这些组的自行车总数相同 (select count(*) from vehicles where v_type = 'bike')
select o.o_id
from owner o
join vehicles v on o.v_id = v.v_id
where v.v_type = 'bike'
group by o.o_id
having count(distinct v.v_id) = (select count(*) from vehicles where v_type = 'bike')
【讨论】：