Question

我有以下表格：

 person( sin, name, address)
 owner(dogowner_id, dog_id, is_primary_owner_of_dog)
 dog( dog_no, breed_id )
 dog_breed( breed_id, breed )

您如何找到至少10个黄色实验室的主要（主要拥有者）的所有人？我对此非常困惑，帮助我非常感激。

编辑：请不要嵌套查询和聚合！

Answer 1

一种方法是在IN表上利用person：

SELECT * FROM person
WHERE sin IN (
    SELECT dogowner_id FROM owner o
        JOIN dog d ON o.dog_id = d.dog_no
        JOIN dog_breed b ON b.breed_id = d.breed_id
    WHERE is_primary_owner_of_dog AND
        b.breed = 'Yellow Lab'
    GROUP BY dogowner_id
    HAVING COUNT(dogowner_id) >= 10
)

内部查询将确定“主要所有者”拥有至少 10只狗的内容，然后外部查询将返回相应的person条记录。

Answer 2

select count(*), dogowner
from owner 
  inner join dog on dog.dog_no = owner.dog_id
  inner join dob_breed on dog.breed_id = dog_breed.breed_id
where dog_breed.breed = 'Yellow Lab'
group by dogowner
having count(*) >=10

Answer 3

您使用join和group by执行此操作：

select dogowner, count(*) as numyellowlabs
from owner o
     dog d
     on o.dog_id = d.dog_no join
     dog_breed db 
     on d.breed_id = db.breed_id
where breed = 'Yellow Lab'
group by dogowner
having count(*) >=10;

Answer 4

SELECT count(*) AS numberOfDogs, dogowner AS dogOwner
FROM owner AS o
  INNER JOIN dog AS d
     ON d.dog_no = o.dog_id
  INNER JOIN dob_breed as b
     ON d.breed_id = b.breed_id
WHERE b.breed = 'Yellow Lab'
   AND o.is_primary_owner_of_dog = "True"
GROUP BY dogowner
HAVING count(*) >=10

其他查询非常接近......缺少的部分是“至少10个黄色实验室的主要（主要拥有者）？”我不知道is_primary_owner_of_dog的值是什么...是/否， 0/1，是/否....因此需要相应地修改查询。但除此之外，这应该可以解决问题。

Answer 5

考虑到不存在嵌套查询和聚合，您可以使用分析函数COUNT（）和连接来完成任务，如下所示：

Select P.*
From Person P Inner Join (Select DISTINCT Dogowner_Id, Count(O.Dog_Id) Over (Partition By O.Dogowner_Id) Dog_Count
From Owner O Inner Join Dog D On O.Dog_Id = D.Dog_No 
Inner Join Dog_Breed Db On D.Breed_Id = Db.Breed_Id
Where   Db.Breed = 'Yellow Lab'
And     O.Is_Primary_Owner_Of_Dog = 1) Counts
On      Counts.Dogowner_Id = P.Sin
Where   Counts.Dog_Count >= 10

拥有至少10只狗的人？

5 个答案: