内部結合3テーブル

私のデータベースにはテーブルがあります booking_system 。そして今、私はcar_space、transaction、sport_facilitiesを内部結合したいと思います。しかし、私は問題があります。内部結合3テーブル

これらの2つのsqlコマンドをそれぞれ使用すると、これらのコマンドを実行して、必要な結果を得ることができます。

-- car_space INNER JOIN transaction 
SELECT * FROM car_space INNER JOIN transaction ON car_space.carSpaceId = transaction.carSpaceId ORDER BY transactionId; 
-- sport_facilities INNER JOIN transaction 
SELECT * FROM sport_facilities INNER JOIN transaction ON sport_facilities.sportFacilitiesId = transaction.sportFacilitiesId ORDER BY transactionId;

次に、これらを1つのコマンドにまとめます。

-- Combine But Not Work 
SELECT * FROM transaction 
INNER JOIN car_space ON transaction.carSpaceId = car_space.carSpaceId 
INNER JOIN sport_facilities ON transaction.sportFacilitiesId = sport_facilities.sportFacilitiesId 
ORDER BY transactionId;

これは実行できますが、結果は表示されませんでした。

私はトランザクションIDを入力したときにテーブル（car_space/sport_facilities）のレコードがデータベースにあります。例： IタイプWHERE transactionId = 1 データベースは、car_spaceではなくsport_facilitiesテーブルから検索できます。

ありがとうございます。参考のためにいくつかのコードがあります。

-- Create a database 
CREATE DATABASE booking_system; 

-- Use This database 
USE booking_system; 

-- Create smartcart table 
CREATE TABLE card(
    cardId CHAR(8)  NOT NULL, 
    PRIMARY KEY (cardId) 
); 

-- Insert some recond to card table 
INSERT INTO card VALUES 
    ('4332A0D5'), 
    ('637ED500'), 
    ('B3895A02'), 
    ('E32F3702') 
; 

-- Create user table 
CREATE TABLE user(
    userId  INT(5)   NOT NULL AUTO_INCREMENT, 
    cardNo  CHAR(8)   NOT NULL, 
    firstName VARCHAR(255) NOT NULL, 
    lastName VARCHAR(255) NOT NULL, 
    sex   CHAR(1)   NOT NULL, 
    dob   DATE   NOT NULL, 
    hkid  CHAR(8)   NOT NULL, 
    email  VARCHAR(255) NOT NULL, 
    telNo  INT(8)   NOT NULL, 
    PRIMARY KEY (userId), 
    FOREIGN KEY (cardNo) REFERENCES card (cardId) ON DELETE CASCADE, 
    UNIQUE (hkid) 
); 

-- Alter user table 
ALTER TABLE user AUTO_INCREMENT = 16001; 

-- Insert some recond to user table 
INSERT INTO user VALUES 
    ('','4332A0D5','Andy','Ding','M','1962-04-20','K5216117','[email protected]','98626229'), 
    ('','637ED500','Emma','Dai','F','1972-06-15','D5060339','[email protected]','62937453'), 
    ('','B3895A02','Brinsley','Au','F','1984-02-24','P8172327','[email protected]','91961624'), 
    ('','E32F3702','Eric','Fong','M','1990-04-15','Y1129323','[email protected]','98428731') 
; 

-- Create car space price table 
CREATE TABLE car_space_price(
    spaceNo    INT(2)  NOT NULL AUTO_INCREMENT, 
    price    INT(2)  NOT NULL, 
    carSpaceDescription VARCHAR(16), 
    CHECK (carSpaceDescription IN ('motorcycles','small vehicles','medium vehicles','large vehicles')), 
    PRIMARY KEY (spaceNo) 
); 

-- Insert some recond to car space price table 
INSERT INTO car_space_price VALUES 
    ('','10','motorcycles'),  -- 1 
    ('','10','motorcycles'),  -- 2 
    ('','10','motorcycles'),  -- 3 
    ('','10','motorcycles'),  -- 4 
    ('','10','motorcycles'),  -- 5 
    ('','20','small vehicles'),  -- 6 
    ('','20','small vehicles'),  -- 7 
    ('','20','small vehicles'),  -- 8 
    ('','20','small vehicles'),  -- 9 
    ('','20','small vehicles'),  -- 10 
    ('','40','medium vehicles'), -- 11 
    ('','40','medium vehicles'), -- 12 
    ('','40','medium vehicles'), -- 13 
    ('','80','large vehicles'),  -- 14 
    ('','80','large vehicles')  -- 15 
; 

-- Create car space table 
CREATE TABLE car_space(
    carSpaceId INT(5)  NOT NULL AUTO_INCREMENT, 
    spaceNo  INT(2)  NOT NULL, 
    cardNo  VARCHAR(8) NOT NULL, 
    inTime  DATETIME, 
    outTime  DATETIME, 
    PRIMARY KEY (carSpaceId), 
    FOREIGN KEY (spaceNo) REFERENCES car_space_price (spaceNo) ON DELETE CASCADE, 
    FOREIGN KEY (cardNo) REFERENCES card (cardId) ON DELETE CASCADE 
); 

-- Insert some recond to car space table 
INSERT INTO car_space VALUES 
    ('','2','E32F3702','2015-02-23 14:24:18','2015-02-23 17:01:43'), -- 1 --16004 
    ('','6','B3895A02','2016-02-24 11:56:43','2016-02-25 09:21:08'), -- 2 --16003 
    ('','2','E32F3702','2016-02-24 16:42:34','2016-02-24 21:02:45'), -- 3 --16004 
    ('','2','E32F3702','2016-02-25 14:25:32','2016-02-25 17:03:54'), -- 4 --16004 
    ('','6','B3895A02','2016-02-25 17:12:11','2016-02-25 20:58:18'), -- 5 --16003 
    ('','13','637ED500','2016-02-25 19:17:03','2016-02-27 18:05:28'), -- 6 --16002 
    ('','6','B3895A02','2016-02-25 21:14:03','2016-02-25 23:53:28'), -- 7 --16003 
    ('','6','B3895A02','2016-02-26 08:46:23','2016-02-26 17:21:08'), -- 8 --16003 
    ('','2','E32F3702','2016-02-26 14:15:45','2016-02-26 21:01:15'), -- 9 --16004 
    ('','6','B3895A02','2016-02-27 09:42:13','2016-02-27 15:48:45'), -- 10 --16003 
    ('','2','E32F3702','2016-02-27 13:25:45','2016-02-27 15:15:45'), -- 11 --16004 
    ('','6','B3895A02','2016-02-28 10:57:16','2016-02-28 14:41:25'), -- 12 --16003 
    ('','2','E32F3702','2016-02-28 11:47:32','2016-02-28 13:43:15'), -- 13 --16004 
    ('','13','637ED500','2016-02-28 13:04:43','2016-03-02 22:39:46'), -- 14 --16002 
    ('','2','E32F3702','2016-02-28 14:42:34','2016-02-28 21:47:45'), -- 15 --16004 
    ('','6','B3895A02','2016-02-29 08:50:42','2016-02-29 14:28:42'), -- 16 --16003 
    ('','2','E32F3702','2016-02-29 12:12:35','2016-02-29 16:45:28'), -- 17 --16004 
    ('','6','B3895A02','2016-03-01 11:26:43','2016-03-01 14:56:26'), -- 18 --16003 
    ('','6','B3895A02','2016-03-03 13:45:26','2016-03-03 17:54:18')  -- 19 --16003 
; 

-- Create sport facilities price table 
CREATE TABLE sport_facilities_price(
    sportNo    INT(2)  NOT NULL AUTO_INCREMENT, 
    sportType   VARCHAR(10) NOT NULL, 
    price    INT(2)  NOT NULL, 
    sportDescription VARCHAR(20), 
    PRIMARY KEY (sportNo) 
); 

-- Insert some recond to sport facilities price table 
INSERT INTO sport_facilities_price VALUES 
    ('','snooker','15','Snooker Room 1'),   -- 1 
    ('','snooker','15','Snooker Room 2'),   -- 2 
    ('','snooker','15','Snooker Room 3'),   -- 3 
    ('','snooker','15','Snooker Room 4'),   -- 4 
    ('','table_tennis','15','Table Tennis Room 1'), -- 5 
    ('','table_tennis','15','Table Tennis Room 2'), -- 6 
    ('','table_tennis','15','Table Tennis Room 3'), -- 7 
    ('','table_tennis','15','Table Tennis Room 4'), -- 8 
    ('','tennis','30','Tennis Vanue 1'),   -- 9 
    ('','tennis','30','Tennis Vanue 2'),   -- 10 
    ('','badminton','30','Badminton Vanue 1'),  -- 11 
    ('','badminton','30','Badminton Vanue 2'),  -- 12 
    ('','basketball','60','Hall')     -- 13 
; 

-- Create sport facilities table 
CREATE TABLE sport_facilities(
    sportFacilitiesId INT(5)  NOT NULL AUTO_INCREMENT, 
    sportNo    INT(2)  NOT NULL, 
    cardNo    VARCHAR(8) NOT NULL, 
    bookDate   DATE  NOT NULL, 
    startTime   TIME  NOT NULL, 
    endTime    TIME  NOT NULL, 
    PRIMARY KEY (sportFacilitiesId), 
    FOREIGN KEY (sportNo) REFERENCES sport_facilities_price (sportNo) ON DELETE CASCADE, 
    FOREIGN KEY (cardNo) REFERENCES card (cardId) ON DELETE CASCADE 
); 

-- Insert some recond to sport facilities table 
INSERT INTO sport_facilities VALUES 
    ('','1','E32F3702','2015-02-23','12:00:00','14:00:00'),  -- 1 --16004 
    ('','5','B3895A02','2016-02-23','14:00:00','15:00:00'),  -- 2 --16003 
    ('','8','637ED500','2016-02-23','17:00:00','21:00:00'),  -- 3 --16002 
    ('','2','E32F3702','2016-02-24','09:00:00','11:00:00'),  -- 4 --16004 
    ('','5','4332A0D5','2016-02-24','13:00:00','14:00:00'),  -- 5 --16001 
    ('','7','637ED500','2016-02-24','15:00:00','17:00:00'),  -- 6 --16002 
    ('','8','B3895A02','2016-02-24','16:00:00','18:00:00'),  -- 7 --16003 
    ('','10','4332A0D5','2016-02-25','09:00:00','10:00:00'), -- 8 --16001 
    ('','12','B3895A02','2016-02-25','13:00:00','14:00:00'), -- 9 --16003 
    ('','6','637ED500','2016-02-25','21:00:00','22:00:00'),  -- 10 --16002 
    ('','4','637ED500','2016-02-26','11:00:00','13:00:00'),  -- 11 --16002 
    ('','8','4332A0D5','2016-02-26','22:00:00','23:00:00'),  -- 12 --16001 
    ('','13','B3895A02','2016-02-27','09:00:00','14:00:00'), -- 13 --16003 
    ('','4','637ED500','2016-02-28','12:00:00','14:00:00'),  -- 14 --16002 
    ('','3','B3895A02','2016-02-28','14:00:00','15:00:00'),  -- 15 --16003 
    ('','4','E32F3702','2016-02-28','17:00:00','19:00:00'),  -- 16 --16004 
    ('','5','B3895A02','2016-02-28','21:00:00','22:00:00'),  -- 17 --16003 
    ('','2','4332A0D5','2016-02-28','21:00:00','23:00:00'),  -- 18 --16001 
    ('','10','E32F3702','2016-02-28','19:00:00','20:00:00'), -- 19 --16004 
    ('','11','B3895A02','2016-02-29','11:00:00','13::00:00'), -- 20 --16003 
    ('','8','E32F3702','2016-02-29','12:00:00','14:00:00'),  -- 21 --16004 
    ('','4','4332A0D5','2016-02-29','15:00:00','18:00:00'),  -- 22 --16001 
    ('','6','E32F3702','2016-03-01','09:00:00','11:00:00'),  -- 23 --16004 
    ('','5','637ED500','2016-03-01','12:00:00','15:00:00'),  -- 24 --16002 
    ('','3','B3895A02','2016-03-02','09:00:00','11:00:00'),  -- 25 --16003 
    ('','7','4332A0D5','2016-03-02','12:00:00','13:00:00'),  -- 26 --16001 
    ('','4','637ED500','2016-03-02','15:00:00','17:00:00'),  -- 27 --16002 
    ('','1','E32F3702','2016-03-02','19:00:00','22:00:00'),  -- 28 --16004 
    ('','12','4332A0D5','2016-03-03','11:00:00','13:00:00'), -- 29 --16001 
    ('','9','E32F3702','2016-03-03','15:00:00','16:00:00'),  -- 30 --16004 
    ('','10','B3895A02','2016-03-03','09:00:00','11:00:00'), -- 31 --16003 
    ('','4','637ED500','2016-03-04','11:00:00','12:00:00'),  -- 32 --16002 
    ('','8','E32F3702','2016-03-04','14:00:00','16:00:00'),  -- 33 --16004 
    ('','6','B3895A02','2016-03-05','19:00:00','21:00:00'),  -- 34 --16003 
    ('','13','E32F3702','2016-03-05','11:00:00','12:00:00'), -- 35 --16004 
    ('','8','637ED500','2016-03-05','14:00:00','15:00:00'),  -- 36 --16002 
    ('','4','4332A0D5','2016-03-05','16:00:00','18:00:00'),  -- 37 --16001 
    ('','5','E32F3702','2016-03-06','13:00:00','15:00:00'),  -- 38 --16004 
    ('','9','B3895A02','2016-03-06','17:00:00','18:00:00'),  -- 39 --16003 
    ('','11','4332A0D5','2016-03-07','20:00:00','21::00:00'), -- 40 --16001 
    ('','5','B3895A02','2016-03-07','22:00:00','23:00:00')  -- 41 --16003 
; 

-- Create transaction table 
CREATE TABLE transaction(
    transactionId  INT(5) UNSIGNED ZEROFILL NOT NULL AUTO_INCREMENT, 
    userId    INT(5) NOT NULL, 
    carSpaceId   INT(5), 
    sportFacilitiesId INT(5), 
    transactionDate  DATE NOT NULL, 
    PRIMARY KEY (transactionId), 
    FOREIGN KEY (userId) REFERENCES user (userId) ON DELETE CASCADE, 
    FOREIGN KEy (carSpaceId) REFERENCES car_space (carSpaceId) ON DELETE CASCADE, 
    FOREIGN KEY (sportFacilitiesId) REFERENCES sport_facilities (sportFacilitiesId) ON DELETE CASCADE 
); 

-- Insert some recond to transaction table 
INSERT INTO transaction VALUES 
    ('','16004',NULL,'1','2015-02-23'),  -- 1 -- Sport Facilities 
    ('','16003',NULL,'5','2015-02-23'),  -- 2 -- Sport Facilities 
    ('','16004','2',NULL,'2015-02-23'),  -- 3 -- Car Space 
    ('','16002',NULL,'8','2015-02-23'),  -- 4 -- Sport Facilities 
    ('','16004',NULL,'2','2016-02-24'),  -- 5 -- Sport Facilities 
    ('','16003','6',NULL,'2016-02-24'),  -- 6 -- Car Space 
    ('','16001',NULL,'5','2016-02-24'),  -- 7 -- Sport Facilities 
    ('','16002',NULL,'7','2016-02-24'),  -- 8 -- Sport Facilities 
    ('','16003',NULL,'8','2016-02-24'),  -- 9 -- Sport Facilities 
    ('','16004','2',NULL,'2016-02-24'),  -- 10 -- Car Space 
    ('','16001',NULL,'10','2016-02-25'), -- 11 -- Sport Facilities 
    ('','16003',NULL,'12','2016-02-25'), -- 12 -- Sport Facilities 
    ('','16004','2',NULL,'2016-02-25'),  -- 13 -- Car Space 
    ('','16003','6',NULL,'2016-02-25'),  -- 14 -- Car Space 
    ('','16002','13',NULL,'2016-02-25'), -- 15 -- Car Space 
    ('','16002',NULL,'6','2016-02-25'),  -- 16 -- Sport Facilities 
    ('','16003','6',NULL,'2016-02-25'),  -- 17 -- Car Space 
    ('','16003','6',NULL,'2016-02-26'),  -- 18 -- Car Space 
    ('','16002',NULL,'4','2016-02-26'),  -- 19 -- Sport Facilities 
    ('','16004','2',NULL,'2016-02-26'),  -- 20 -- Car Space 
    ('','16001',NULL,'8','2016-02-26'),  -- 21 -- Sport Facilities 
    ('','16003',NULL,'13','2016-02-27'), -- 22 -- Sport Facilities 
    ('','16003','6',NULL,'2016-02-27'),  -- 23 -- Car Space 
    ('','16004','2',NULL,'2016-02-27'),  -- 24 -- Car Space 
    ('','16003','6',NULL,'2016-02-28'),  -- 25 -- Car Space 
    ('','16004','2',NULL,'2016-02-28'),  -- 26 -- Car Space 
    ('','16002',NULL,'4','2016-02-28'),  -- 27 -- Sport Facilities 
    ('','16002','13',NULL,'2016-02-28'), -- 28 -- Car Space 
    ('','16003',NULL,'3','2016-02-28'),  -- 29 -- Sport Facilities 
    ('','16004','2',NULL,'2016-02-28'),  -- 30 -- Car Space 
    ('','16004',NULL,'4','2016-02-28'),  -- 31 -- Sport Facilities 
    ('','16003',NULL,'5','2016-02-28'),  -- 32 -- Sport Facilities 
    ('','16001',NULL,'2','2016-02-28'),  -- 33 -- Sport Facilities 
    ('','16004',NULL,'10','2016-02-28'), -- 34 -- Sport Facilities 
    ('','16003','6',NULL,'2016-02-29'),  -- 35 -- Car Space 
    ('','16003',NULL,'11','2016-02-29'), -- 36 -- Sport Facilities 
    ('','16004',NULL,'8','2016-02-29'),  -- 37 -- Sport Facilities 
    ('','16004','2',NULL,'2016-02-29'),  -- 38 -- Car Space 
    ('','16001',NULL,'4','2016-02-29'),  -- 39 -- Sport Facilities 
    ('','16004',NULL,'6','2016-03-01'),  -- 40 -- Sport Facilities 
    ('','16003','6',NULL,'2016-03-01'),  -- 41 -- Car Space 
    ('','16002',NULL,'5','2016-03-01'),  -- 42 -- Sport Facilities 
    ('','16003',NULL,'3','2016-03-02'),  -- 43 -- Sport Facilities 
    ('','16001',NULL,'7','2016-03-02'),  -- 44 -- Sport Facilities 
    ('','16002',NULL,'4','2016-03-02'),  -- 45 -- Sport Facilities 
    ('','16004',NULL,'1','2016-03-02'),  -- 46 -- Sport Facilities 
    ('','16001',NULL,'12','2016-03-03'), -- 47 -- Sport Facilities 
    ('','16003','6',NULL,'2016-03-03'),  -- 48 -- Car Space 
    ('','16004',NULL,'9','2016-03-03'),  -- 49 -- Sport Facilities 
    ('','16003',NULL,'10','2016-03-03'), -- 50 -- Sport Facilities 
    ('','16002',NULL,'4','2016-03-04'),  -- 51 -- Sport Facilities 
    ('','16004',NULL,'8','2016-03-04'),  -- 52 -- Sport Facilities 
    ('','16003',NULL,'6','2016-03-05'),  -- 53 -- Sport Facilities 
    ('','16004',NULL,'13','2016-03-05'), -- 54 -- Sport Facilities 
    ('','16002',NULL,'8','2016-03-05'),  -- 55 -- Sport Facilities 
    ('','16001',NULL,'4','2016-03-05'),  -- 56 -- Sport Facilities 
    ('','16004',NULL,'5','2016-03-06'),  -- 57 -- Sport Facilities 
    ('','16003',NULL,'9','2016-03-06'),  -- 58 -- Sport Facilities 
    ('','16001',NULL,'11','2016-03-07'), -- 59 -- Sport Facilities 
    ('','16003',NULL,'5','2016-03-07')  -- 60 -- Sport Facilities 
;

出典

2016-03-26 Donald Chi Chung Fok

どのように行を結合しますか？

車のスペースを参照するすべての取引がNULLのスポーツ施設参照を持つように見えます。逆も同様です。

照会は行単位で行われます。INNER JOINトランザクションを車のスペースだけにすると、車のスペースレコードを含むすべてのトランザクションレコードを車のスペースレコードとともに取得します。他のすべてのトランザクションは除外されます。

スポーツ施設へのINNER JOINを追加すると、一致する行がなくなり、不一致の行が除外されます。これにより空の結果セットが残されます。

二重INNER JOINクエリから結果を得るには、取引行は車のスペースとスポーツ施設を参照（またはリンク）する必要があります。

車のスペースまたはスポーツ施設のいずれかを使用してトランザクション行をすべて保持し、参照されていないものについてはNULLレコードを残したい場合は、INNER JOINをLEFT JOINに変更することができますあなたの最終的な質問）。

出典

2016-03-26 19:03:17 Arth

この場合、UNION演算子を使用したいと考えています。両方のテーブルで一致するトランザクションIDがないため、0行が返されます。 LEFT/FULLジョインも機能します。

SELECT * FROM car_space INNER JOIN transaction ON car_space.carSpaceId = transaction.carSpaceId ORDER BY transactionId; 
UNION 
SELECT * FROM sport_facilities INNER JOIN transaction ON sport_facilities.sportFacilitiesId = transaction.sportFacilitiesId ORDER BY transactionId;

出典

2016-03-26 22:20:23

UNIONはここでは機能しません。sports_facilityテーブルには複数の列がありますが、2つの表が似ているように見えるかもしれません。 – Arth

答えて

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