Tournament results (Swiss pairings system)

Description

Database model and a bunch of methods which could be used to implemente a game tournament that uses the Swiss pairings system. This system is used for pairing up players in each round: players are not eliminated, and each player should be paired with another player with the same number of wins, or as close as possible.

Requirements

• Postgresql
• psycopg2 python's postgresql library

Installation

First of all, you will need to create a database called tournament. Choose your preferred way to create such database in Postgres, for instance (UNIX based OS command line):

$ createdb tournament

Then, connect to the fresh created database:

$ psql tournament

And execute SQL's script:

tournament=> \i tournament.sql

Output should be:

CREATE TABLE
CREATE TABLE
CREATE VIEW
CREATE VIEW
CREATE VIEW
CREATE VIEW
CREATE VIEW

And you will end with a schema like this:

Schema	Name	Type
public	matches	table
public	matches_id_seq	sequence
public	player_standings	view
public	player_standings_even	view
public	player_standings_odd	view
public	players	table
public	players_id_seq	sequence
public	total_matches	view
public	total_wins	view

Run tests

A set of tests is included, to launch them you need to type (from project's root dir):

$ python tournament_test.py

And if it everything goes well, output should be:

1. Old matches can be deleted.
2. Player records can be deleted.
3. After deleting, countPlayers() returns zero.
4. After registering a player, countPlayers() returns 1.
5. Players can be registered and deleted.
6. Newly registered players appear in the standings with no matches.
7. After a match, players have updated standings.
8. After one match, players with one win are paired.
Success!  All tests pass!