飞行(Flight_Id,日期,发件人,收件人)
客运(PASSENGER_NAME,性别)
票(TICKET_ID,Flight_Id,PASSENGER_NAME,类,价格)
我知道如何找到谁买了多张票的乘客。但不知道如何找到只买了两张票的乘客。
飞行(Flight_Id,日期,发件人,收件人)
客运(PASSENGER_NAME,性别)
票(TICKET_ID,Flight_Id,PASSENGER_NAME,类,价格)
我知道如何找到谁买了多张票的乘客。但不知道如何找到只买了两张票的乘客。
两张票 选择PASSENGER_NAME FROM票证T INNER上p.Passenger_Name = t.Passenger_Name 组加入乘客P BY PASSENGER_NAME HAVING COUNT(1)= 2;
多于一张门票
选择PASSENGER_NAME FROM票证T INNER JOIN乘客P 上p.Passenger_Name = t.Passenger_Name GROUP BY PASSENGER_NAME HAVING COUNT(1)> 1;
如果你想谁买了整整两个票航班,然后乘客:如果你想谁买多一票的航班,然后乘客
SELECT Passenger_Name,
Flight_Id
FROM Ticket
GROUP BY Passenger_Name,
Flight_Id
HAVING COUNT(Ticket_Id) = 2;
:
SELECT Passenger_Name,
Flight_Id
FROM Ticket
GROUP BY Passenger_Name,
Flight_Id
HAVING COUNT(Ticket_Id) > 1;
哪个RDBMS这是因为你已经为MySQL或Oracle标记了它吗? – MT0
对不起,你们看到我的照片了? – user92322
这是查询范例 – user92322