I have written this in both C and Java. It is very complex as, in real
life, you want to balance home and away, sequence the games so that the home
or away games are spread throughout the schedule, accomodate partial rounds
(10 team league where each team is to play 13 games), accomodate odd numbers
of teams (7,9,etc.) and create games for teams with short schedules and a
lot more. In addition, this is only the beginning as, once you have a
playing schedule, you need to assign the games to space which is much more
complicated than creating the schedule. Reporting the games is rather
trivial except for situations where games have been moved, teams have
dropped out or been forfeited out, etc.
Thanks,
Carl
Gavin - Sorry, didn't mean to send it to you privately... itchy trigger
finger.
----- Original Message -----
From: "Gavin Towey" <gto...@ffn.com>
To: "Tompkins Neil" <neil.tompk...@googlemail.com>; "[MySQL]"
<mysql@lists.mysql.com>
Sent: Thursday, August 19, 2010 1:50 PM
Subject: RE: Fixture List generation using MySQL
That's almost a cartesean product; except you just want to eliminate results
where a team would be paired up with itself.
create table teams ( id serial );
Query OK, 0 rows affected (0.02 sec)
insert into teams values (), (), (), ();
Query OK, 4 rows affected (0.05 sec)
Records: 4 Duplicates: 0 Warnings: 0
[ff] test> select * from teams;
+----+
| id |
+----+
| 1 |
| 2 |
| 3 |
| 4 |
+----+
4 rows in set (0.00 sec)
select * from locations;
+------+
| name |
+------+
| home |
| away |
+------+
2 rows in set (0.00 sec)
select * from teams t1 JOIN teams t2;
+----+----+
| id | id |
+----+----+
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 1 | 2 |
| 2 | 2 |
| 3 | 2 |
| 4 | 2 |
| 1 | 3 |
| 2 | 3 |
| 3 | 3 |
| 4 | 3 |
| 1 | 4 |
| 2 | 4 |
| 3 | 4 |
| 4 | 4 |
+----+----+
16 rows in set (0.00 sec)
With no join condition, we every possible combination of t1 paired with t2;
however, this leads to the undesireable result that we have combinations
like team 4 vs team 4. So you just need to add a condition to prevent those
rows from showing up:
select * from teams t1 JOIN teams t2 ON t1.id!=t2.id;
+----+----+
| id | id |
+----+----+
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 1 | 2 |
| 3 | 2 |
| 4 | 2 |
| 1 | 3 |
| 2 | 3 |
| 4 | 3 |
| 1 | 4 |
| 2 | 4 |
| 3 | 4 |
+----+----+
12 rows in set (0.10 sec)
Notice you get both combinations of 2 vs 1 and 1 vs 2, so you could just
call whichever team is in the first column as the "home team."
Regards,
Gavin Towey
-----Original Message-----
From: Tompkins Neil [mailto:neil.tompk...@googlemail.com]
Sent: Thursday, August 19, 2010 10:07 AM
To: [MySQL]
Subject: Re: Fixture List generation using MySQL
I'm looking at a routine / script to create the fixtures like
team 1 vs team 2
team 3 vs team 4
team 5 vs team 6 etc
On Thu, Aug 19, 2010 at 3:44 PM, Peter Brawley <
peter.braw...@earthlink.net> wrote:
I'm tasked with generating a list of fixtures from a table of teams,
whereby
each team plays each other home and away. Does anyone have any
experience
generating such information using MySQL ?
Basically ...
select a.id,b.id from tbl a join tbl b on a.id<b.id;
union
select a.id,b.id from tbl a join tbl b on a.id>b.id;
PB
-----
On 8/19/2010 9:12 AM, Tompkins Neil wrote:
Hi,
I'm tasked with generating a list of fixtures from a table of teams,
whereby
each team plays each other home and away. Does anyone have any
experience
generating such information using MySQL ?
Thanks for any input.
Regards
Neil
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