Question

(SELECT COUNT(motorbike.`owner_id`) as count,owner.`name`,transport.`type` FROM transport,owner,motorbike WHERE transport.type='motobike'
AND owner.`owner_id`=motorbike.`owner_id`
AND transport.`type_id`=motorbike.`motorbike_id` GROUP BY motorbike.owner_id)
UNION ALL
(SELECT COUNT(car.`owner_id`) as count,owner.`name`,transport.`type` FROM transport,owner,car WHERE transport.type='car'
AND owner.`owner_id`=car.`owner_id`
AND transport.`type_id`=car.`car_id` GROUP BY car.`owner_id`)

上面的查询返回如下所示的结果

count          name
1              Linda
2              Mary
1              Steve
1              Linda

此查询用于计算所有者拥有的传输数量。琳达有一辆车和一辆摩托车，结果应该是：

count          name
2              Linda
2              Mary
1              Steve

我已尝试过此查询，但返回错误：

(SELECT COUNT(motorbike.`owner_id`),owner.`name`,transport.`type` FROM transport,owner,motorbike WHERE transport.type='motobike'
AND owner.`owner_id`=motorbike.`owner_id`
AND transport.`type_id`=motorbike.`motorbike_id`)
UNION ALL
(SELECT COUNT(car.`owner_id`),owner.`name`,transport.`type` FROM transport,owner,car WHERE transport.type='car'
AND owner.`owner_id`=car.`owner_id`
AND transport.`type_id`=car.`car_id`)  GROUP BY motorbike.owner_id

有人可以帮我吗？

Answer 1

select sum(qty), name
from (
    select count(m.owner_id) as qty, o.name
    from transport t,owner o,motorbike m
    where t.type='motobike' and o.owner_id=m.owner_id
        and t.type_id=m.motorbike_id
    group by m.owner_id

    union all

    select count(c.owner_id) as qty, o.name,
    from transport t,owner o,car c
    where t.type='car' and o.owner_id=c.owner_id and t.type_id=c.car_id
    group by c.owner_id
) t
group by name

Answer 2

这可能是你的事后：

SELECT Count(Owner_ID), Name
FROM (
    SELECT M.Owner_ID, O.Name, T.Type
    FROM Transport As T, Owner As O, Motorbike As M
    WHERE T.Type = 'Motorbike'
    AND O.Owner_ID = M.Owner_ID
    AND T.Type_ID = M.Motorbike_ID

    UNION ALL

    SELECT C.Owner_ID, O.Name, T.Type
    FROM Transport As T, Owner As O, Car As C
    WHERE T.Type = 'Car'
    AND O.Owner_ID = C.Owner_ID
    AND T.Type_ID = C.Car_ID
)
GROUP BY Owner_ID

Answer 3

试试这个编辑：

(SELECT COUNT(motorbike.owner_id),owner.name,transport.type FROM transport,owner,motorbike WHERE transport.type='motobike' AND owner.owner_id=motorbike.owner_id AND transport.type_id=motorbike.motorbike_id GROUP BY motorbike.owner_id)

UNION ALL

(SELECT COUNT(car.owner_id),owner.name,transport.type FROM transport,owner,car WHERE transport.type='car' AND owner.owner_id=car.owner_id AND transport.type_id=car.car_id GROUP BY car.owner_id)

group by with union mysql select query

3 个答案: