數據庫請求

Question

我想要做如下要求我的數據庫：

我尋找誰與他人擔任男主角（作業）在10分鐘的電影togehter工作人員。你有任何提示或建議，我該如何解決這個問題？

• PRODUCTION（生產，標題）
• MOVIE（生產 - >生產，型）
• 人（人，名稱，實名，birth_country）WORKS（人 - >
• PERSON，生產 - >生產作業）

Answer 1

這似乎像這類問題更適合像的Neo4j圖形數據庫，但在這裏是一個關係型SQL解決方案：

select w1.person as person1 
     , w2.person as person2 
     , count(w1.production) as joint_productions 
from works w1 
    join works w2 
      on w1.production = w2.production 
where w1.person != w2.person 
group by w1.person, w2.person having count(w1.production) >= 10 
order by w1.person, w2.person; 

這顯示了演員和他們在一起的電影數量。它包括的倒數，即

bill murray, dan ackroyd, 10 
dan ackroyd, bill murray, 10 

如果你只是想將一組名稱，你可以這樣做：

select distinct w1.person 
from works w1 
    join works w2 
      on w1.production = w2.production 
where w1.person != w2.person 
group by w1.person, w2.person having count(w1.production) >= 10 
order by w1.person; 

Answer 2

我可能會發現沒有一個子請求的解決方案。這是對的嗎？

select w1.person as person1, w2.person as person2, p1.name , p2.name, count(w1.production) as joint_productions 
from works w1 join works w2 on w1.production = w2.production 
join person p1 on w1.person = p1.person 
join person p2 on w2.person = p2.person 
where w1.person != w2.person 
group by w1.person, p1.name, p2.name, w2.person having count(w1.production) 
>= 10 order by w1.person, w2.person