Question

我有两张表格如下：

select * from passenger_1038299 
where passengerid in(select passengerid from flight_1038299 
                     group by passengerid 
                     having count(passengerid)>1);

问题是：

列出乘坐航班ID的乘客详细信息，该航班ID已在多个航班中旅行。（此功能将显示乘客的详细信息及其在多个航班中旅行的航班ID。）

我使用了这个查询：

imgur.com

但它并没有给我flight_ids。请告诉我如何检索航班ID。感谢和抱歉愚蠢的问题，作为sql的新手。

Answer 1

加入航班表以获取乘客的航班

select * from passenger_1038299 p
join flight_1038299 f on f.passenger_id = p.passenger_id
where p.passengerid in(
    select passengerid from flight_1038299 group by passengerid having count(passengerid)>1
);

我喜欢使用exists来检查倍数。使用passenger_id上的索引，它可能比上面的查询运行得更快。

select * from passenger_1038299 p
join flight_1038299 f on f.passenger_id = p.passenger_id
where exists (
  select 1 from flight_1038299 f2 
  where f2.passenger_id = f.passenger_id
  and f2.flight_id <> f.flight_id
)

修改

使用count窗口函数的另一种方法：

select * from ( select *, count() over (partition by p.passenger_id) cnt from passenger_1038299 p join flight_1038299 f on f.passenger_id = p.passenger_id ) t where cnt > 1

Answer 2

使用分析函数的另一种方法：

SELECT * FROM (
    SELECT p.*, f.flight_id,
           count(*) OVER (PARTITION BY f.passenger_id ) As number_of_flights
    FROM passenger p
    JOIN flight f
    ON p.passenger_id = f.passenger_id
)
WHERE number_of_flights > 1

演示：http://sqlfiddle.com/#!4/dab21/11

Answer 3

试试这种方式

航班ID应为多个，因此以逗号分隔列。

select a.*,b.flightid from passenger_1038299 a
join (select passengerid,Stuff((SELECT ', ' + s.flight_id 
         FROM flight_1038299 l
         where c.passengerid = l.passengerid
         FOR XML PATH('')),1,1,'') flightid from flight_1038299 as c group by c.passengerid having count(c.passengerid)>1) b on a.passengerid=b.passengerid

sql query- group by然后加入

3 个答案: