如何在其他两个联接之间执行联接
How do I perform a join between two other joins
我想知道如何执行 2 个执行计划：“传统”执行计划连接（A 与 B）然后连接 C。
“新”计划加入（A 与 B），然后加入（A 与 C），然后加入这些加入的结果，因此会有 3 个加入。 根据以下代码，我将如何在 Oracle SQLPlus 中对传统计划和新计划进行编码？我还需要测量这两种方法的时间复杂度，以表明新计划花费的时间更少，我相信我只需打开 set timer 即可；连接可以基于任何有效的属性。与 select 语句相同。我制作了一个艺术家，b 专辑，c 曲目，d 播放。
这是数据库：
CREATE TABLE artist(
artist_id INTEGER NOT NULL,
artist_name CHAR(128) DEFAULT NULL,
PRIMARY KEY (artist_id)
);
CREATE TABLE album (
artist_id INTEGER NOT NULL,
album_id INTEGER NOT NULL,
album_name CHAR(128) DEFAULT NULL,
PRIMARY KEY (artist_id,album_id),
FOREIGN KEY (artist_id) REFERENCES artist(artist_id)
);
CREATE TABLE track (
track_id INTEGER NOT NULL,
track_name CHAR(128) DEFAULT NULL,
artist_id INTEGER NOT NULL,
album_id INTEGER NOT NULL,
time DECIMAL(5,2) DEFAULT NULL,
PRIMARY KEY (artist_id,album_id,track_id),
FOREIGN KEY (artist_id) REFERENCES artist(artist_id),
FOREIGN KEY (artist_id,album_id) REFERENCES album(artist_id,album_id)
);
CREATE TABLE played (
artist_id INTEGER NOT NULL,
album_id INTEGER NOT NULL,
track_id INTEGER NOT NULL,
played date DEFAULT sysdate, -- TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
PRIMARY KEY (artist_id,album_id,track_id,played),
FOREIGN KEY (artist_id) REFERENCES artist(artist_id),
FOREIGN KEY (artist_id,album_id) REFERENCES album(artist_id,album_id),
FOREIGN KEY (artist_id,album_id,track_id) REFERENCES track(artist_id,album_id,track_id)
);
INSERT INTO artist VALUES (1, 'New Order');
INSERT INTO artist VALUES (2, 'Nick Cave The Bad Seeds');
INSERT INTO artist VALUES (3, 'Miles Davis');
INSERT INTO artist VALUES (4, 'The Rolling Stones');
INSERT INTO artist VALUES (5, 'The Stone Roses');
INSERT INTO artist VALUES (6, 'Kylie Minogue');
INSERT INTO album VALUES (2, 1, 'Let Love In');
INSERT INTO album VALUES (1, 1, 'Retro - John McCready FAN');
INSERT INTO album VALUES (1, 2, 'Substance (Disc 2)');
INSERT INTO album VALUES (1, 3, 'Retro - Miranda Sawyer POP');
INSERT INTO album VALUES (1, 4, 'Retro - New Order / Bobby Gillespie LIVE');
INSERT INTO album VALUES (3, 1, 'Live Around The World');
INSERT INTO album VALUES (3, 2, 'In A Silent Way');
INSERT INTO album VALUES (1, 5, 'Power, Corruption Lies');
INSERT INTO album VALUES (4, 1, 'Exile On Main Street');
INSERT INTO album VALUES (1, 6, 'Substance 1987 (Disc 1)');
INSERT INTO album VALUES (5, 1, 'Second Coming');
INSERT INTO album VALUES (6, 1, 'Light Years');
INSERT INTO album VALUES (1, 7, 'Brotherhood');
INSERT INTO track VALUES (0,'Do You Love Me?',2,1,'5.95');
INSERT INTO track VALUES (1,'Nobodys Baby Now',2,1,'3.87');
INSERT INTO track VALUES (2,'Loverman',2,1,'6.37');
INSERT INTO track VALUES (3,'Jangling Jack',2,1,'2.78');
INSERT INTO track VALUES (4,'Red Right Hand',2,1,'6.18');
INSERT INTO track VALUES (5,'I Let Love In',2,1,'4.25');
INSERT INTO track VALUES (6,'Thirsty Dog',2,1,'3.81');
INSERT INTO track VALUES (7,'Aint Gonna Rain Anymore',2,1,'3.77');
INSERT INTO track VALUES (8,'Lay Me Low',2,1,'5.15');
INSERT INTO track VALUES (9,'Do You Love Me? (Part Two)',2,1,'6.23');
INSERT INTO track VALUES (0,'Elegia',1,1,'4.93');
INSERT INTO track VALUES (1,'In A Lonely Place',1,1,'6.26');
INSERT INTO track VALUES (2,'Procession',1,1,'4.47');
INSERT INTO track VALUES (3,'Your Silent Face',1,1,'5.99');
INSERT INTO track VALUES (4,'Sunrise',1,1,'6.01');
INSERT INTO track VALUES (5,'Lets Go',1,1,'3.90');
INSERT INTO track VALUES (6,'Broken Promise',1,1,'3.76');
INSERT INTO track VALUES (7,'Dreams Never End',1,1,'3.20');
INSERT INTO track VALUES (8,'Cries And Whispers',1,1,'3.42');
INSERT INTO track VALUES (9,'All Day Long',1,1,'5.18');
INSERT INTO track VALUES (10,'Sooner Than You Think',1,1,'5.21');
INSERT INTO track VALUES (11,'Leave Me Alone',1,1,'4.67');
INSERT INTO track VALUES (12,'Lonesome Tonight',1,1,'5.19');
INSERT INTO track VALUES (13,'Every Little Counts',1,1,'4.47');
INSERT INTO track VALUES (14,'Run Wild',1,1,'3.95');
INSERT INTO track VALUES (0,'In A Lonely Place',1,2,'6.30');
INSERT INTO track VALUES (1,'Procession',1,2,'4.46');
INSERT INTO track VALUES (2,'Mesh',1,2,'3.44');
INSERT INTO track VALUES (3,'Hurt',1,2,'6.98');
INSERT INTO track VALUES (4,'The Beach',1,2,'7.32');
INSERT INTO track VALUES (5,'Confusion',1,2,'7.64');
INSERT INTO track VALUES (6,'Lonesome Tonight',1,2,'5.20');
INSERT INTO track VALUES (7,'Murder',1,2,'3.93');
INSERT INTO track VALUES (8,'Thieves Like Us',1,2,'6.95');
INSERT INTO track VALUES (9,'Kiss Of Death',1,2,'7.05');
INSERT INTO track VALUES (10,'Shame Of The Nation',1,2,'7.91');
INSERT INTO track VALUES (11,'1963',1,2,'5.63');
INSERT INTO track VALUES (0,'Fine Time',1,3,'4.71');
INSERT INTO track VALUES (1,'Temptation',1,3,'8.71');
INSERT INTO track VALUES (2,'True Faith',1,3,'5.88');
INSERT INTO track VALUES (3,'The Perfect Kiss',1,3,'4.83');
INSERT INTO track VALUES (4,'Ceremony',1,3,'4.41');
INSERT INTO track VALUES (5,'Regret',1,3,'4.14');
INSERT INTO track VALUES (6,'Crystal',1,3,'6.83');
INSERT INTO track VALUES (7,'Bizarre Love Triangle',1,3,'4.35');
INSERT INTO track VALUES (8,'Confusion',1,3,'8.22');
INSERT INTO track VALUES (9,'Round And Round',1,3,'4.52');
INSERT INTO track VALUES (10,'Blue Monday',1,3,'7.48');
INSERT INTO track VALUES (11,'Brutal',1,3,'4.83');
INSERT INTO track VALUES (12,'Slow Jam',1,3,'4.88');
INSERT INTO track VALUES (13,'Everyone Everywhere',1,3,'4.43');
INSERT INTO track VALUES (0,'Ceremony [Studio 54, Barcelona 7/7/84]',1,4,'4.82');
INSERT INTO track VALUES (1,'Procession [Polytechnic of Central London, London 6/12/85]',1,4,'3.57');
INSERT INTO track VALUES (2,'Everythings Gone Green [Tolworth Recreation Centre, London 12/3/85]',1,4,'5.25');
INSERT INTO track VALUES (3,'In A Lonely Place [Glastonbury Festival 20/6/81]',1,4,'5.55');
INSERT INTO track VALUES (4,'Age Of Consent [Spectrum Arena, Warrington 1/3/86]',1,4,'5.04');
INSERT INTO track VALUES (5,'Elegia [Glastonbury Festival 19/6/87]',1,4,'4.77');
INSERT INTO track VALUES (6,'The Perfect Kiss [Glastonbury Festival 19/6/87]',1,4,'9.73');
INSERT INTO track VALUES (7,'Fine Time [Popular Creek Music Theatre, Chicago 30/6/89]',1,4,'5.04');
INSERT INTO track VALUES (8,'World [Starplex Amphitheatre, Dallas 21/7/93]',1,4,'4.81');
INSERT INTO track VALUES (9,'Regret [Reading Festival 29/8/93]',1,4,'4.03');
INSERT INTO track VALUES (10,'As It Is When It Was [Reading Festival 29/8/93]',1,4,'3.80');
INSERT INTO track VALUES (11,'Intermission By Alan Wise [Olympia, Paris 12/11/01]',1,4,'1.34');
INSERT INTO track VALUES (12,'Crystal [Big Day Out, Gold Coast 20/1/02]',1,4,'6.86');
INSERT INTO track VALUES (13,'Turn My Way [Olympia, Liverpool 18/7/01]',1,4,'4.96');
INSERT INTO track VALUES (14,'Temptation [Big Day Out, Gold Coast 20/1/02]',1,4,'7.79');
INSERT INTO track VALUES (0,'In A Silent Way',3,1,'1.81');
INSERT INTO track VALUES (1,'Intruder',3,1,'4.87');
INSERT INTO track VALUES (2,'New Blues',3,1,'5.58');
INSERT INTO track VALUES (3,'Human Nature',3,1,'12.80');
INSERT INTO track VALUES (4,'Mr. Pastorius',3,1,'3.54');
INSERT INTO track VALUES (5,'Amandla',3,1,'5.87');
INSERT INTO track VALUES (6,'Wrinkle',3,1,'7.28');
INSERT INTO track VALUES (7,'Tutu',3,1,'8.89');
INSERT INTO track VALUES (8,'Full Nelson',3,1,'2.81');
INSERT INTO track VALUES (9,'Time After Time',3,1,'9.98');
INSERT INTO track VALUES (10,'Hannibal',3,1,'7.37');
INSERT INTO track VALUES (0,'Shhh/Peaceful',3,2,'16.67');
INSERT INTO track VALUES (1,'In A Silent Way/It\s About That Time',3,2,'16.67');
INSERT INTO track VALUES (0,'Age Of Consent',1,5,'5.26');
INSERT INTO track VALUES (1,'We All Stand',1,5,'5.24');
INSERT INTO track VALUES (2,'The Village',1,5,'4.62');
INSERT INTO track VALUES (3,'5 8 6',1,5,'7.52');
INSERT INTO track VALUES (4,'Your Silent Face',1,5,'6.00');
INSERT INTO track VALUES (5,'Ultraviolence',1,5,'4.87');
INSERT INTO track VALUES (6,'Ecstasy',1,5,'4.42');
INSERT INTO track VALUES (7,'Leave Me Alone',1,5,'4.69');
INSERT INTO track VALUES (0,'Rocks Off',4,1,'4.54');
INSERT INTO track VALUES (1,'Rip This Joint',4,1,'2.38');
INSERT INTO track VALUES (2,'Shake Your Hips',4,1,'3.00');
INSERT INTO track VALUES (3,'Casino Boogie',4,1,'3.57');
INSERT INTO track VALUES (4,'Tumbling Dice',4,1,'3.79');
INSERT INTO track VALUES (5,'Sweet Virginia',4,1,'4.44');
INSERT INTO track VALUES (6,'Torn Frayed',4,1,'4.30');
INSERT INTO track VALUES (7,'Sweet Black Angel',4,1,'2.97');
INSERT INTO track VALUES (8,'Loving Cup',4,1,'4.43');
INSERT INTO track VALUES (9,'Happy',4,1,'3.08');
INSERT INTO track VALUES (10,'Turd On The Run',4,1,'2.64');
INSERT INTO track VALUES (11,'Ventilator Blues',4,1,'3.40');
INSERT INTO track VALUES (12,'I Just Want To See His Face',4,1,'2.90');
INSERT INTO track VALUES (13,'Let It Loose',4,1,'5.31');
INSERT INTO track VALUES (14,'All Down The Line',4,1,'3.84');
INSERT INTO track VALUES (15,'Stop Breaking Down',4,1,'4.57');
INSERT INTO track VALUES (16,'Shine A Light',4,1,'4.28');
INSERT INTO track VALUES (17,'Soul Survivor',4,1,'3.82');
INSERT INTO track VALUES (0,'Ceremony',1,6,'4.42');
INSERT INTO track VALUES (1,'Everythings Gone Green',1,6,'5.51');
INSERT INTO track VALUES (2,'Temptation',1,6,'6.99');
INSERT INTO track VALUES (3,'Blue Monday',1,6,'7.49');
INSERT INTO track VALUES (4,'Confusion',1,6,'4.72');
INSERT INTO track VALUES (5,'Thieves Like Us',1,6,'6.61');
INSERT INTO track VALUES (6,'Perfect Kiss',1,6,'8.04');
INSERT INTO track VALUES (7,'Subculture',1,6,'4.80');
INSERT INTO track VALUES (8,'Shellshock',1,6,'6.48');
INSERT INTO track VALUES (9,'State of the Nation',1,6,'6.54');
INSERT INTO track VALUES (10,'Bizarre Love Triangle',1,6,'6.74');
INSERT INTO track VALUES (11,'True Faith',1,6,'5.93');
INSERT INTO track VALUES (0,'Breaking Into Heaven',5,1,'11.37');
INSERT INTO track VALUES (1,'Driving South',5,1,'5.17');
INSERT INTO track VALUES (2,'Ten Storey Love Song',5,1,'4.50');
INSERT INTO track VALUES (3,'Daybreak',5,1,'6.56');
INSERT INTO track VALUES (4,'Your Star Will Shine',5,1,'2.99');
INSERT INTO track VALUES (5,'Straight To The Man',5,1,'3.26');
INSERT INTO track VALUES (6,'Begging You',5,1,'4.94');
INSERT INTO track VALUES (7,'Tightrope',5,1,'4.45');
INSERT INTO track VALUES (8,'Good Times',5,1,'5.67');
INSERT INTO track VALUES (9,'Tears',5,1,'6.84');
INSERT INTO track VALUES (10,'How Do You Sleep',5,1,'4.99');
INSERT INTO track VALUES (11,'Love Spreads',5,1,'5.79');
INSERT INTO track VALUES (12,'Untitled',5,1,'6.43');
INSERT INTO track VALUES (0,'Spinning Around',6,1,'3.46');
INSERT INTO track VALUES (1,'On A Night Like This',6,1,'3.55');
INSERT INTO track VALUES (2,'So Now Goodbye',6,1,'3.62');
INSERT INTO track VALUES (3,'Disco Down',6,1,'3.96');
INSERT INTO track VALUES (4,'Loveboat',6,1,'4.18');
INSERT INTO track VALUES (5,'Koocachoo',6,1,'4.00');
INSERT INTO track VALUES (6,'Your Disco Needs You',6,1,'3.56');
INSERT INTO track VALUES (7,'Please Stay',6,1,'4.14');
INSERT INTO track VALUES (8,'Bittersweet Goodbye',6,1,'3.72');
INSERT INTO track VALUES (9,'Butterfly',6,1,'4.16');
INSERT INTO track VALUES (10,'Under The Influence Of Love',6,1,'3.40');
INSERT INTO track VALUES (11,'I am So High',6,1,'3.55');
INSERT INTO track VALUES (12,'Kids',6,1,'4.34');
INSERT INTO track VALUES (0,'State of the Nation',1,7,'6.56');
INSERT INTO track VALUES (1,'Every Little Counts',1,7,'4.48');
INSERT INTO track VALUES (2,'Angel Dust',1,7,'3.73');
INSERT INTO track VALUES (3,'All Day Long',1,7,'5.21');
INSERT INTO track VALUES (4,'Bizarre Love Triangle',1,7,'4.37');
INSERT INTO track VALUES (5,'Way of Life',1,7,'4.11');
INSERT INTO track VALUES (6,'Broken Promise',1,7,'3.80');
INSERT INTO track VALUES (7,'As It Is When It Was',1,7,'3.77');
INSERT INTO track VALUES (8,'Weirdo',1,7,'3.89');
INSERT INTO track VALUES (9,'Paradise',1,7,'3.86');
INSERT INTO played VALUES (1, 3, 0, '5-jan-2019');
INSERT INTO played VALUES (1, 3, 1, '25-feb-2020');
INSERT INTO played VALUES (1, 3, 2, '15-jan-2020');
INSERT INTO played VALUES (1, 3, 3, '7-jan-2019');
INSERT INTO played VALUES (1, 3, 4, '9-jan-2019');
INSERT INTO played VALUES (1, 3, 5, '21-jan-2019');
INSERT INTO played VALUES (1, 3, 6, '11-jan-2019');
INSERT INTO played VALUES (1, 3, 7, '30-jan-2019');
INSERT INTO played VALUES (3, 1, 0, '8-jan-2020');
INSERT INTO played VALUES (3, 1, 1, '28-jan-2019');
INSERT INTO played VALUES (3, 1, 2, '3-jan-2019');
你的问题没有多大意义，因为它施加了我们无法真正评估的奇怪限制，但我不介意告诉你如何连接两个连接
您已经知道如何在 normal/traditional/sensible 意义上连接三个 table。以下是如何按照您的要求加入他们：
SELECT ...
FROM
(SELECT a.id, ... FROM a JOIN b ON ...) ab
JOIN (SELECT a.id, ... FROM a JOIN c ON ...) ac ON ac.id = ab.id
快讯：sql join 对“数据块”进行操作，而不仅仅是 tables。 table 是一个数据块，SELECT 的输出也是。您可以获取 select 输出的任何数据，并将其馈送到任何需要数据块以供查询的地方。在大多数数据库中，您甚至可以使用 WITH
将它们变成伪 table
WITH ab as (SELECT a.id, ... FROM a JOIN b ON ...),
ac as (SELECT a.id, ... FROM a JOIN c ON ...)
SELECT ...
FROM ab JOIN ac ON ac.id = ab.id
这也使得它们很容易在同一个查询中多次重用
SELECT ...
FROM
ab
JOIN ac ac1 ON ac1.id = ab.id
JOIN ac ac2 ON ac2.id = ab.id
快讯 2：优化器很可能会查看子查询形式或 WITH 形式并重写它，以便它的执行与您已经拥有的两个连接路由相同。让数据库在性能方面成为市场领导者的很大一部分是将开发人员扔进其中的垃圾重写为性能尽可能好的东西。在计算出一组连接操作后，这些查询都归结为同一件事，您可能不会看到查询的执行方式有任何变化
我想知道如何执行 2 个执行计划：“传统”执行计划连接（A 与 B）然后连接 C。 “新”计划加入（A 与 B），然后加入（A 与 C），然后加入这些加入的结果，因此会有 3 个加入。 根据以下代码，我将如何在 Oracle SQLPlus 中对传统计划和新计划进行编码？我还需要测量这两种方法的时间复杂度，以表明新计划花费的时间更少，我相信我只需打开 set timer 即可；连接可以基于任何有效的属性。与 select 语句相同。我制作了一个艺术家，b 专辑，c 曲目，d 播放。
这是数据库：
CREATE TABLE artist(
artist_id INTEGER NOT NULL,
artist_name CHAR(128) DEFAULT NULL,
PRIMARY KEY (artist_id)
);
CREATE TABLE album (
artist_id INTEGER NOT NULL,
album_id INTEGER NOT NULL,
album_name CHAR(128) DEFAULT NULL,
PRIMARY KEY (artist_id,album_id),
FOREIGN KEY (artist_id) REFERENCES artist(artist_id)
);
CREATE TABLE track (
track_id INTEGER NOT NULL,
track_name CHAR(128) DEFAULT NULL,
artist_id INTEGER NOT NULL,
album_id INTEGER NOT NULL,
time DECIMAL(5,2) DEFAULT NULL,
PRIMARY KEY (artist_id,album_id,track_id),
FOREIGN KEY (artist_id) REFERENCES artist(artist_id),
FOREIGN KEY (artist_id,album_id) REFERENCES album(artist_id,album_id)
);
CREATE TABLE played (
artist_id INTEGER NOT NULL,
album_id INTEGER NOT NULL,
track_id INTEGER NOT NULL,
played date DEFAULT sysdate, -- TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
PRIMARY KEY (artist_id,album_id,track_id,played),
FOREIGN KEY (artist_id) REFERENCES artist(artist_id),
FOREIGN KEY (artist_id,album_id) REFERENCES album(artist_id,album_id),
FOREIGN KEY (artist_id,album_id,track_id) REFERENCES track(artist_id,album_id,track_id)
);
INSERT INTO artist VALUES (1, 'New Order');
INSERT INTO artist VALUES (2, 'Nick Cave The Bad Seeds');
INSERT INTO artist VALUES (3, 'Miles Davis');
INSERT INTO artist VALUES (4, 'The Rolling Stones');
INSERT INTO artist VALUES (5, 'The Stone Roses');
INSERT INTO artist VALUES (6, 'Kylie Minogue');
INSERT INTO album VALUES (2, 1, 'Let Love In');
INSERT INTO album VALUES (1, 1, 'Retro - John McCready FAN');
INSERT INTO album VALUES (1, 2, 'Substance (Disc 2)');
INSERT INTO album VALUES (1, 3, 'Retro - Miranda Sawyer POP');
INSERT INTO album VALUES (1, 4, 'Retro - New Order / Bobby Gillespie LIVE');
INSERT INTO album VALUES (3, 1, 'Live Around The World');
INSERT INTO album VALUES (3, 2, 'In A Silent Way');
INSERT INTO album VALUES (1, 5, 'Power, Corruption Lies');
INSERT INTO album VALUES (4, 1, 'Exile On Main Street');
INSERT INTO album VALUES (1, 6, 'Substance 1987 (Disc 1)');
INSERT INTO album VALUES (5, 1, 'Second Coming');
INSERT INTO album VALUES (6, 1, 'Light Years');
INSERT INTO album VALUES (1, 7, 'Brotherhood');
INSERT INTO track VALUES (0,'Do You Love Me?',2,1,'5.95');
INSERT INTO track VALUES (1,'Nobodys Baby Now',2,1,'3.87');
INSERT INTO track VALUES (2,'Loverman',2,1,'6.37');
INSERT INTO track VALUES (3,'Jangling Jack',2,1,'2.78');
INSERT INTO track VALUES (4,'Red Right Hand',2,1,'6.18');
INSERT INTO track VALUES (5,'I Let Love In',2,1,'4.25');
INSERT INTO track VALUES (6,'Thirsty Dog',2,1,'3.81');
INSERT INTO track VALUES (7,'Aint Gonna Rain Anymore',2,1,'3.77');
INSERT INTO track VALUES (8,'Lay Me Low',2,1,'5.15');
INSERT INTO track VALUES (9,'Do You Love Me? (Part Two)',2,1,'6.23');
INSERT INTO track VALUES (0,'Elegia',1,1,'4.93');
INSERT INTO track VALUES (1,'In A Lonely Place',1,1,'6.26');
INSERT INTO track VALUES (2,'Procession',1,1,'4.47');
INSERT INTO track VALUES (3,'Your Silent Face',1,1,'5.99');
INSERT INTO track VALUES (4,'Sunrise',1,1,'6.01');
INSERT INTO track VALUES (5,'Lets Go',1,1,'3.90');
INSERT INTO track VALUES (6,'Broken Promise',1,1,'3.76');
INSERT INTO track VALUES (7,'Dreams Never End',1,1,'3.20');
INSERT INTO track VALUES (8,'Cries And Whispers',1,1,'3.42');
INSERT INTO track VALUES (9,'All Day Long',1,1,'5.18');
INSERT INTO track VALUES (10,'Sooner Than You Think',1,1,'5.21');
INSERT INTO track VALUES (11,'Leave Me Alone',1,1,'4.67');
INSERT INTO track VALUES (12,'Lonesome Tonight',1,1,'5.19');
INSERT INTO track VALUES (13,'Every Little Counts',1,1,'4.47');
INSERT INTO track VALUES (14,'Run Wild',1,1,'3.95');
INSERT INTO track VALUES (0,'In A Lonely Place',1,2,'6.30');
INSERT INTO track VALUES (1,'Procession',1,2,'4.46');
INSERT INTO track VALUES (2,'Mesh',1,2,'3.44');
INSERT INTO track VALUES (3,'Hurt',1,2,'6.98');
INSERT INTO track VALUES (4,'The Beach',1,2,'7.32');
INSERT INTO track VALUES (5,'Confusion',1,2,'7.64');
INSERT INTO track VALUES (6,'Lonesome Tonight',1,2,'5.20');
INSERT INTO track VALUES (7,'Murder',1,2,'3.93');
INSERT INTO track VALUES (8,'Thieves Like Us',1,2,'6.95');
INSERT INTO track VALUES (9,'Kiss Of Death',1,2,'7.05');
INSERT INTO track VALUES (10,'Shame Of The Nation',1,2,'7.91');
INSERT INTO track VALUES (11,'1963',1,2,'5.63');
INSERT INTO track VALUES (0,'Fine Time',1,3,'4.71');
INSERT INTO track VALUES (1,'Temptation',1,3,'8.71');
INSERT INTO track VALUES (2,'True Faith',1,3,'5.88');
INSERT INTO track VALUES (3,'The Perfect Kiss',1,3,'4.83');
INSERT INTO track VALUES (4,'Ceremony',1,3,'4.41');
INSERT INTO track VALUES (5,'Regret',1,3,'4.14');
INSERT INTO track VALUES (6,'Crystal',1,3,'6.83');
INSERT INTO track VALUES (7,'Bizarre Love Triangle',1,3,'4.35');
INSERT INTO track VALUES (8,'Confusion',1,3,'8.22');
INSERT INTO track VALUES (9,'Round And Round',1,3,'4.52');
INSERT INTO track VALUES (10,'Blue Monday',1,3,'7.48');
INSERT INTO track VALUES (11,'Brutal',1,3,'4.83');
INSERT INTO track VALUES (12,'Slow Jam',1,3,'4.88');
INSERT INTO track VALUES (13,'Everyone Everywhere',1,3,'4.43');
INSERT INTO track VALUES (0,'Ceremony [Studio 54, Barcelona 7/7/84]',1,4,'4.82');
INSERT INTO track VALUES (1,'Procession [Polytechnic of Central London, London 6/12/85]',1,4,'3.57');
INSERT INTO track VALUES (2,'Everythings Gone Green [Tolworth Recreation Centre, London 12/3/85]',1,4,'5.25');
INSERT INTO track VALUES (3,'In A Lonely Place [Glastonbury Festival 20/6/81]',1,4,'5.55');
INSERT INTO track VALUES (4,'Age Of Consent [Spectrum Arena, Warrington 1/3/86]',1,4,'5.04');
INSERT INTO track VALUES (5,'Elegia [Glastonbury Festival 19/6/87]',1,4,'4.77');
INSERT INTO track VALUES (6,'The Perfect Kiss [Glastonbury Festival 19/6/87]',1,4,'9.73');
INSERT INTO track VALUES (7,'Fine Time [Popular Creek Music Theatre, Chicago 30/6/89]',1,4,'5.04');
INSERT INTO track VALUES (8,'World [Starplex Amphitheatre, Dallas 21/7/93]',1,4,'4.81');
INSERT INTO track VALUES (9,'Regret [Reading Festival 29/8/93]',1,4,'4.03');
INSERT INTO track VALUES (10,'As It Is When It Was [Reading Festival 29/8/93]',1,4,'3.80');
INSERT INTO track VALUES (11,'Intermission By Alan Wise [Olympia, Paris 12/11/01]',1,4,'1.34');
INSERT INTO track VALUES (12,'Crystal [Big Day Out, Gold Coast 20/1/02]',1,4,'6.86');
INSERT INTO track VALUES (13,'Turn My Way [Olympia, Liverpool 18/7/01]',1,4,'4.96');
INSERT INTO track VALUES (14,'Temptation [Big Day Out, Gold Coast 20/1/02]',1,4,'7.79');
INSERT INTO track VALUES (0,'In A Silent Way',3,1,'1.81');
INSERT INTO track VALUES (1,'Intruder',3,1,'4.87');
INSERT INTO track VALUES (2,'New Blues',3,1,'5.58');
INSERT INTO track VALUES (3,'Human Nature',3,1,'12.80');
INSERT INTO track VALUES (4,'Mr. Pastorius',3,1,'3.54');
INSERT INTO track VALUES (5,'Amandla',3,1,'5.87');
INSERT INTO track VALUES (6,'Wrinkle',3,1,'7.28');
INSERT INTO track VALUES (7,'Tutu',3,1,'8.89');
INSERT INTO track VALUES (8,'Full Nelson',3,1,'2.81');
INSERT INTO track VALUES (9,'Time After Time',3,1,'9.98');
INSERT INTO track VALUES (10,'Hannibal',3,1,'7.37');
INSERT INTO track VALUES (0,'Shhh/Peaceful',3,2,'16.67');
INSERT INTO track VALUES (1,'In A Silent Way/It\s About That Time',3,2,'16.67');
INSERT INTO track VALUES (0,'Age Of Consent',1,5,'5.26');
INSERT INTO track VALUES (1,'We All Stand',1,5,'5.24');
INSERT INTO track VALUES (2,'The Village',1,5,'4.62');
INSERT INTO track VALUES (3,'5 8 6',1,5,'7.52');
INSERT INTO track VALUES (4,'Your Silent Face',1,5,'6.00');
INSERT INTO track VALUES (5,'Ultraviolence',1,5,'4.87');
INSERT INTO track VALUES (6,'Ecstasy',1,5,'4.42');
INSERT INTO track VALUES (7,'Leave Me Alone',1,5,'4.69');
INSERT INTO track VALUES (0,'Rocks Off',4,1,'4.54');
INSERT INTO track VALUES (1,'Rip This Joint',4,1,'2.38');
INSERT INTO track VALUES (2,'Shake Your Hips',4,1,'3.00');
INSERT INTO track VALUES (3,'Casino Boogie',4,1,'3.57');
INSERT INTO track VALUES (4,'Tumbling Dice',4,1,'3.79');
INSERT INTO track VALUES (5,'Sweet Virginia',4,1,'4.44');
INSERT INTO track VALUES (6,'Torn Frayed',4,1,'4.30');
INSERT INTO track VALUES (7,'Sweet Black Angel',4,1,'2.97');
INSERT INTO track VALUES (8,'Loving Cup',4,1,'4.43');
INSERT INTO track VALUES (9,'Happy',4,1,'3.08');
INSERT INTO track VALUES (10,'Turd On The Run',4,1,'2.64');
INSERT INTO track VALUES (11,'Ventilator Blues',4,1,'3.40');
INSERT INTO track VALUES (12,'I Just Want To See His Face',4,1,'2.90');
INSERT INTO track VALUES (13,'Let It Loose',4,1,'5.31');
INSERT INTO track VALUES (14,'All Down The Line',4,1,'3.84');
INSERT INTO track VALUES (15,'Stop Breaking Down',4,1,'4.57');
INSERT INTO track VALUES (16,'Shine A Light',4,1,'4.28');
INSERT INTO track VALUES (17,'Soul Survivor',4,1,'3.82');
INSERT INTO track VALUES (0,'Ceremony',1,6,'4.42');
INSERT INTO track VALUES (1,'Everythings Gone Green',1,6,'5.51');
INSERT INTO track VALUES (2,'Temptation',1,6,'6.99');
INSERT INTO track VALUES (3,'Blue Monday',1,6,'7.49');
INSERT INTO track VALUES (4,'Confusion',1,6,'4.72');
INSERT INTO track VALUES (5,'Thieves Like Us',1,6,'6.61');
INSERT INTO track VALUES (6,'Perfect Kiss',1,6,'8.04');
INSERT INTO track VALUES (7,'Subculture',1,6,'4.80');
INSERT INTO track VALUES (8,'Shellshock',1,6,'6.48');
INSERT INTO track VALUES (9,'State of the Nation',1,6,'6.54');
INSERT INTO track VALUES (10,'Bizarre Love Triangle',1,6,'6.74');
INSERT INTO track VALUES (11,'True Faith',1,6,'5.93');
INSERT INTO track VALUES (0,'Breaking Into Heaven',5,1,'11.37');
INSERT INTO track VALUES (1,'Driving South',5,1,'5.17');
INSERT INTO track VALUES (2,'Ten Storey Love Song',5,1,'4.50');
INSERT INTO track VALUES (3,'Daybreak',5,1,'6.56');
INSERT INTO track VALUES (4,'Your Star Will Shine',5,1,'2.99');
INSERT INTO track VALUES (5,'Straight To The Man',5,1,'3.26');
INSERT INTO track VALUES (6,'Begging You',5,1,'4.94');
INSERT INTO track VALUES (7,'Tightrope',5,1,'4.45');
INSERT INTO track VALUES (8,'Good Times',5,1,'5.67');
INSERT INTO track VALUES (9,'Tears',5,1,'6.84');
INSERT INTO track VALUES (10,'How Do You Sleep',5,1,'4.99');
INSERT INTO track VALUES (11,'Love Spreads',5,1,'5.79');
INSERT INTO track VALUES (12,'Untitled',5,1,'6.43');
INSERT INTO track VALUES (0,'Spinning Around',6,1,'3.46');
INSERT INTO track VALUES (1,'On A Night Like This',6,1,'3.55');
INSERT INTO track VALUES (2,'So Now Goodbye',6,1,'3.62');
INSERT INTO track VALUES (3,'Disco Down',6,1,'3.96');
INSERT INTO track VALUES (4,'Loveboat',6,1,'4.18');
INSERT INTO track VALUES (5,'Koocachoo',6,1,'4.00');
INSERT INTO track VALUES (6,'Your Disco Needs You',6,1,'3.56');
INSERT INTO track VALUES (7,'Please Stay',6,1,'4.14');
INSERT INTO track VALUES (8,'Bittersweet Goodbye',6,1,'3.72');
INSERT INTO track VALUES (9,'Butterfly',6,1,'4.16');
INSERT INTO track VALUES (10,'Under The Influence Of Love',6,1,'3.40');
INSERT INTO track VALUES (11,'I am So High',6,1,'3.55');
INSERT INTO track VALUES (12,'Kids',6,1,'4.34');
INSERT INTO track VALUES (0,'State of the Nation',1,7,'6.56');
INSERT INTO track VALUES (1,'Every Little Counts',1,7,'4.48');
INSERT INTO track VALUES (2,'Angel Dust',1,7,'3.73');
INSERT INTO track VALUES (3,'All Day Long',1,7,'5.21');
INSERT INTO track VALUES (4,'Bizarre Love Triangle',1,7,'4.37');
INSERT INTO track VALUES (5,'Way of Life',1,7,'4.11');
INSERT INTO track VALUES (6,'Broken Promise',1,7,'3.80');
INSERT INTO track VALUES (7,'As It Is When It Was',1,7,'3.77');
INSERT INTO track VALUES (8,'Weirdo',1,7,'3.89');
INSERT INTO track VALUES (9,'Paradise',1,7,'3.86');
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你的问题没有多大意义，因为它施加了我们无法真正评估的奇怪限制，但我不介意告诉你如何连接两个连接
您已经知道如何在 normal/traditional/sensible 意义上连接三个 table。以下是如何按照您的要求加入他们：
SELECT ...
FROM
(SELECT a.id, ... FROM a JOIN b ON ...) ab
JOIN (SELECT a.id, ... FROM a JOIN c ON ...) ac ON ac.id = ab.id
快讯：sql join 对“数据块”进行操作，而不仅仅是 tables。 table 是一个数据块，SELECT 的输出也是。您可以获取 select 输出的任何数据，并将其馈送到任何需要数据块以供查询的地方。在大多数数据库中，您甚至可以使用 WITH
将它们变成伪 tableWITH ab as (SELECT a.id, ... FROM a JOIN b ON ...),
ac as (SELECT a.id, ... FROM a JOIN c ON ...)
SELECT ...
FROM ab JOIN ac ON ac.id = ab.id
这也使得它们很容易在同一个查询中多次重用
SELECT ...
FROM
ab
JOIN ac ac1 ON ac1.id = ab.id
JOIN ac ac2 ON ac2.id = ab.id
快讯 2：优化器很可能会查看子查询形式或 WITH 形式并重写它，以便它的执行与您已经拥有的两个连接路由相同。让数据库在性能方面成为市场领导者的很大一部分是将开发人员扔进其中的垃圾重写为性能尽可能好的东西。在计算出一组连接操作后，这些查询都归结为同一件事，您可能不会看到查询的执行方式有任何变化