Otra solución de Oracle.
Configuración :
CREATE TABLE League (
LeagueID INT PRIMARY KEY,
LeagueName VARCHAR(30) UNIQUE
);
CREATE TABLE Team (
TeamID INT PRIMARY KEY,
TeamAbbreviation CHAR(3) UNIQUE,
TeamName VARCHAR(50) UNIQUE,
LeagueID INT CONSTRAINT FK_Team_League REFERENCES League(LeagueID)
);
CREATE TABLE Fixture (
FixtureID INT PRIMARY KEY,
WeekNumber INT NOT NULL,
FixtureDate DATE NULL,
HomeTeamID INT NULL,
AwayTeamID INT NULL,
LeagueID INT CONSTRAINT FK_Fixture_League REFERENCES League(LeagueID)
);
INSERT INTO League VALUES ( 1, 'League 1' );
INSERT INTO League VALUES ( 2, 'League 2' );
INSERT INTO Team VALUES ( 1, 'AAA', 'Team A', 1 );
INSERT INTO Team VALUES ( 2, 'BBB', 'Team B', 1 );
INSERT INTO Team VALUES ( 3, 'CCC', 'Team C', 1 );
INSERT INTO Team VALUES ( 4, 'DDD', 'Team D', 1 );
INSERT INTO Team VALUES ( 5, 'EEE', 'Team E', 2 );
INSERT INTO Team VALUES ( 6, 'FFF', 'Team F', 2 );
INSERT INTO Team VALUES ( 7, 'GGG', 'Team G', 2 );
INSERT INTO Team VALUES ( 8, 'HHH', 'Team H', 2 );
INSERT INTO Team VALUES ( 9, 'III', 'Team I', 2 );
Insertar - Accesorios :
INSERT INTO Fixture
WITH league_teams ( id, leagueid, idx, is_fake, num_teams, num_fake ) AS (
-- Generate a unique-per-league index for each team that is between 0
-- and the (number of teams - 1) and calculate the number of teams
-- and if this is an odd number then generate a fake team as well.
SELECT TeamID,
LeagueID,
ROW_NUMBER() OVER ( PARTITION BY LeagueID ORDER BY TeamID ) - 1,
0,
COUNT(1) OVER ( PARTITION BY LeagueID ),
MOD( COUNT(1) OVER ( PARTITION BY LeagueID ), 2 )
FROM Team
UNION ALL
SELECT NULL,
LeagueID,
COUNT(1),
1,
COUNT(1),
1
FROM Team
GROUP BY LeagueID
HAVING MOD( COUNT(1), 2 ) > 0
),
cte ( home_idx, away_idx, week_number, leagueID, num_teams, num_fake ) AS (
-- Start by calculating the round 1 games
SELECT idx,
num_teams + num_fake - 1 - idx,
1,
LeagueID,
num_teams,
num_fake
FROM league_teams
WHERE 2 * idx < num_teams
UNION ALL
-- Then generate the successive rounds with the two cases when the
-- away team has the maximum index or otherwise.
SELECT CASE away_idx
WHEN num_teams + num_fake - 1
THEN home_idx + 1
ELSE MOD( home_idx + 1, num_teams + num_fake -1 )
END,
CASE away_idx
WHEN num_teams + num_fake - 1
THEN away_idx
ELSE MOD( away_idx + 1, num_teams + num_fake - 1 )
END,
week_number + 1,
LeagueID,
num_teams,
num_fake
FROM cte
WHERE week_number < num_teams + num_fake - 1
)
-- Finally join the cte results back to the League_Teams table to convert
-- the indexes used in calculation back to the actual team ids.
SELECT rn,
week_number,
NULL,
h.id,
a.id,
c.leagueid
FROM (
-- This step isn't necessary but it keeps the results in a nice order.
SELECT ROWNUM AS rn,
t.*
FROM (
-- Duplicate the results swapping home and away.
SELECT week_number,
home_idx,
away_idx,
LeagueId
FROM cte
UNION ALL
SELECT week_number + num_teams + num_fake - 1,
away_idx,
home_idx,
LeagueId
FROM cte
) t
) c
INNER JOIN League_Teams h
ON ( c.home_idx = h.idx AND c.leagueId = h.leagueID )
INNER JOIN League_Teams a
ON ( c.away_idx = a.idx AND c.leagueId = a.leagueID )
ORDER BY rn;
Salida :
SELECT * FROM fixture;
FIXTUREID WEEKNUMBER FIXTUREDATE HOMETEAMID AWAYTEAMID LEAGUEID
---------- ---------- ------------------- ---------- ---------- ----------
1 1 1 4 1
2 1 2 3 1
3 1 5 2
4 1 6 9 2
5 1 7 8 2
6 2 2 4 1
7 2 3 1 1
8 2 6 2
9 2 7 5 2
10 2 8 9 2
11 3 3 4 1
12 3 1 2 1
13 3 7 2
14 3 8 6 2
15 3 9 5 2
16 4 8 2
17 4 9 7 2
18 4 5 6 2
19 5 9 2
20 5 5 8 2
21 5 6 7 2
22 4 4 1 1
23 4 3 2 1
24 6 5 2
25 6 9 6 2
26 6 8 7 2
27 5 4 2 1
28 5 1 3 1
29 7 6 2
30 7 5 7 2
31 7 9 8 2
32 6 4 3 1
33 6 2 1 1
34 8 7 2
35 8 6 8 2
36 8 5 9 2
37 9 8 2
38 9 7 9 2
39 9 6 5 2
40 10 9 2
41 10 8 5 2
42 10 7 6 2
(Nota:FixtureDate es NULL ya que no está claro cómo desea que se genere esto, pero debería poder tomar el número de semana y usarlo como la compensación desde el inicio de la temporada para generar fechas)
