Best way to design tournament database

I think that using the team ID is the right way to go. Another level of abstraction for all of the finals rounds just adds unnecessary complexity for not much benefit other than pre-loading the matches table with data.

The data structure looks pretty solid to support this. The quarter and semi finals would need to be added to the matches table once the initial match results are in. If the matches are assigned randomly then this is a manual operation, however, if they are in a particular order...

   A
match 1 -----+
   B         A
          match 5 -----+
   C         C         |
match 2 -----+         |
   D                   A
                    match 7
   E                   F
match 3 -----+         |
   F         F         |
          match 6 -----+
   G         G
match 4 -----+
   H

...then this could possibly be done with a query. Again, the complexity of the query may not be worth the effort depending on the number of teams

I'd start off by trying to fix all the predetermined information in the model itself including

• dates/venues
• structure (ie group/knockout stages)
• rules (ie points scoring, tie-break rules)

Some of this information will be data in tables, some will be codified logic in views.

Something like this perhaps:

• team(team_id, group_code enum('A', 'B', 'C', 'D'), name)
• match(match_id, kickoff_at)
• group_match(match_id, team_id_home, team_id_away, group_code)
• knockout_match(match_id, knockout_code enum('Q1', 'Q2', 'Q3', 'Q4', 'S1', 'S2', 'F')
• result(match_id, score_home, score_away)

Information such which teams play in Q1 never needs to be stored directly because it can be calculated from the group stage results. The only changes to make as the tournament progresses are inserts into the result table.