I want to represent a database for football championships. How can I represent that a class "Match" is played between two classes "Team"?
You can represent multiple associations between the same classes in a UML class diagram by drawing separate association lines, each with its distinct role names to clarify the different relationships.
classDiagram
class Team {
+List<Match> homeMatches
+List<Match> awayMatches
}
class Match {
+Team homeTeam
+Team awayTeam
}
Team "1" --> "*" Match : homeMatches
Team "1" --> "*" Match : awayMatches
The role names "homeMatches" and "awayMatches" distinguish the two different associations between Match and Team3. This clearly shows that:
A match involves exactly one home team and exactly one away team. A team can participate in multiple matches as either the home or away team. When implementing this in code, these associations would typically become attributes in the Match class.
ref:
https://softwareengineering.stackexchange.com/questions/345395/does-uml-allow-multiple-relations-between-2-classes