我有2张桌子，桌子飞行和桌子离开都有
Table flight:
flightnr| dest | start
| |
--------------------------------
| |
LH100 | ATL | FRA
LH102 | DXB | FRA
LH103 | ORD | FRA
LH104 | HND | FRA
LH105 | LHR | FRA
LH106 | LAX | FRA
LH107 | HKG | FRA
LH108 | CDG | FRA
LH109 | DFW | FRA
LH110 | IST | FRA
LH200 | ATL | LHR
LH201 | PEK | LHR
LH202 | DXB | LHR
LH203 | ORD | LHR
LH204 | FRA | LHR
另一个表是
Table departure:
flightnr| date | sign
| |
---------------------------------------
| |
LH-100 | 2018-01-10 | D-ABBL
LH-100 | 2018-02-10 | D-ABBL
LH-100 | 2018-03-10 | D-ABBL
LH-100 | 2018-04-10 | D-ABBL
LH-100 | 2018-05-10 | D-ABBL
LH-100 | 2018-06-10 | D-ABBL
LH-100 | 2018-07-10 | D-ABBK
LH-100 | 2018-08-10 | D-ABBK
LH-102 | 2018-02-10 | D-ABBB
LH-102 | 2018-04-10 | D-ABBB
LH-102 | 2018-06-10 | D-ABBB
LH-103 | 2018-09-10 | D-ABBB
LH-104 | 2018-03-10 | D-ABBB
LH-104 | 2018-05-10 | D-ABBB
LH-104 | 2018-07-10 | D-ABBB
LH-104 | 2018-09-10 | D-ABBB
LH-105 | 2018-01-10 | D-ABBB
LH-105 | 2018-02-10 | D-ABBB
LH-105 | 2018-03-10 | D-ABBB
LH-200 | 2018-01-10 | D-ABCA
LH-200 | 2018-02-10 | D-ABCA
LH-201 | 2018-03-10 | D-ABCA
LH-201 | 2018-05-10 | D-ABBR
LH-202 | 2018-05-10 | D-ABCA
LH-202 | 2018-09-10 | D-ABCA
LH-203 | 2018-04-10 | D-ABCA
LH-203 | 2018-05-10 | D-ABCA
LH-203 | 2018-06-10 | D-ABCC
LH-204 | 2018-01-10 | D-ABBF
LH-204 | 2018-03-10 | D-ABBI
LH-204 | 2018-08-10 | D-ABBM
所以现在我要选择使我有可能从iata'FRA'飞往'PEK'的航线，这是我无法在1班次中起飞的，因为没有从'FRA'到'PEK'的直接航班在桌子出发。
作为客户，我必须先从“ FRA”飞到“ LHR”，然后才能从“ LHR”飞到“ PEK”。
我现在的问题是，我真的不知道如何选择能使我从“ FRA”飞到“ PEK”的线。输出应该是这样的：
date | flightnr | start | change_over_dest | date | flightnr | change_over_start | dest
------------+--------+-------+--------------+------------+--------+---------------+------
2018-03-10| LH-105 | FRA | LHR | 2018-03-10| LH-201 | LHR | PEK
2018-03-10| LH-105 | FRA | LHR | 2018-05-10| LH-201 | LHR | PEK
我已经尝试了在两个表之间使用JOINS的许多不同版本（使用2个JOINS加入到自身的航班，然后出发），但是它们都没有以正确的方式起作用。
希望我以清楚的方式描述了我的问题，你们可以帮助我。
问候
Zeroza
答案 0 :(得分：0)
我们可以尝试在flight表上进行自联接，条件是第一个目的地是第二条路线的起点。此外，我们可以限制起始和最终目的地城市。请注意，我们还将flight表加入到每个departure表中，以输入出发日期。
SELECT
d1.date AS date_start,
f1.flightnr AS flightnr_start,
f1.start AS first_start,
f1.dest AS change_over_dest,
d2.date AS date_end,
f2.flightnr AS flightnr_end,
f2.start AS last_start,
f2.dest AS change_over_end
FROM flight f1
INNER JOIN departure d1
ON f1.flightnr = d1.flightnr
INNER JOIN flight f2
ON f1.dest = f2.start
INNER JOIN departure d2
ON f2.flightnr = d2.flightnr AND d1.date = d2.date
WHERE
f1.start = 'FRA' AND f2.dest = 'PEK';
我没有打扰围绕您的完整样本数据集进行演示，因为它充满了错别字。相反，我只是在下面设置了一个简单的演示，它似乎正在工作。
答案 1 :(得分：0)
DROP TABLE IF EXISTS fight;
CREATE TABLE flight
(flightnr CHAR(5) NOT NULL PRIMARY KEY
,destination CHAR(3) NOT NULL
,start CHAR(3) NOT NULL
);
INSERT INTO flight VALUES
('LH100','ATL','FRA'),
('LH102','DXB','FRA'),
('LH103','ORD','FRA'),
('LH104','HND','FRA'),
('LH105','LHR','FRA'),
('LH106','LAX','FRA'),
('LH107','HKG','FRA'),
('LH108','CDG','FRA'),
('LH109','DFW','FRA'),
('LH110','IST','FRA'),
('LH200','ATL','LHR'),
('LH201','PEK','LHR'),
('LH202','DXB','LHR'),
('LH203','ORD','LHR'),
('LH204','FRA','LHR');
DROP TABLE IF EXISTS departure;
CREATE TABLE departure
(flightnr CHAR(5) NOT NULL
,date DATE NOT NULL
,sign CHAR(6) NOT NULL
,PRIMARY KEY(flightnr,date)
);
INSERT INTO departure VALUES
('LH100','2018-10-01','D-ABBL'),
('LH100','2018-10-02','D-ABBL'),
('LH100','2018-10-03','D-ABBL'),
('LH100','2018-10-04','D-ABBL'),
('LH100','2018-10-05','D-ABBL'),
('LH100','2018-10-06','D-ABBL'),
('LH100','2018-10-07','D-ABBK'),
('LH100','2018-10-08','D-ABBK'),
('LH102','2018-10-02','D-ABBB'),
('LH102','2018-10-04','D-ABBB'),
('LH102','2018-10-06','D-ABBB'),
('LH103','2018-10-09','D-ABBB'),
('LH104','2018-10-03','D-ABBB'),
('LH104','2018-10-05','D-ABBB'),
('LH104','2018-10-07','D-ABBB'),
('LH104','2018-10-09','D-ABBB'),
('LH105','2018-10-01','D-ABBB'),
('LH105','2018-10-02','D-ABBB'),
('LH105','2018-10-03','D-ABBB'),
('LH200','2018-10-01','D-ABCA'),
('LH200','2018-10-02','D-ABCA'),
('LH201','2018-10-03','D-ABCA'),
('LH201','2018-10-05','D-ABBR'),
('LH202','2018-10-05','D-ABCA'),
('LH202','2018-10-09','D-ABCA'),
('LH203','2018-10-04','D-ABCA'),
('LH203','2018-10-05','D-ABCA'),
('LH203','2018-10-06','D-ABCC'),
('LH204','2018-10-01','D-ABBF'),
('LH204','2018-10-03','D-ABBI'),
('LH204','2018-10-08','D-ABBM');
SELECT f1.flightnr
, f1.start
, d1.date startdate
, f2.flightnr transferflightnr
, f2.start transferlocation
, d2.date transferdate
, f2.destination
FROM flight f1
JOIN departure d1
ON d1.flightnr = f1.flightnr
JOIN flight f2
ON f2.start = f1.destination
JOIN departure d2
ON d2.flightnr = f2.flightnr
AND d2.date >= d1.date
WHERE f2.destination = 'pek'
AND f1.start = 'fra';
+----------+-------+------------+------------------+------------------+--------------+-------------+
| flightnr | start | startdate | transferflightnr | transferlocation | transferdate | destination |
+----------+-------+------------+------------------+------------------+--------------+-------------+
| LH105 | FRA | 2018-10-01 | LH201 | LHR | 2018-10-03 | PEK |
| LH105 | FRA | 2018-10-02 | LH201 | LHR | 2018-10-03 | PEK |
| LH105 | FRA | 2018-10-03 | LH201 | LHR | 2018-10-03 | PEK |
| LH105 | FRA | 2018-10-01 | LH201 | LHR | 2018-10-05 | PEK |
| LH105 | FRA | 2018-10-02 | LH201 | LHR | 2018-10-05 | PEK |
| LH105 | FRA | 2018-10-03 | LH201 | LHR | 2018-10-05 | PEK |
+----------+-------+------------+------------------+------------------+--------------+-------------+