Question

Let’s say we have a Player table and a Team table and one-to-many relationship between them (a Player is a member of one Team only or a member of none)

So I have a nullable team_id field in Player table, referencing to a Team table.

But now I have to store an extra information about a player’s position in the team. Like:

• isCaptain
• number
• etc…

What is the right (normal) way to implement this?

My best ideas is an extra table:

Player one-to-one (NULL) PlayerTeam many-to-one (not NULL) Team

Answer 1

I would recommend your own suggestion making a new table:

id | player_id | team_id | role_id | number

and then make player_id unique, and team_id not null.

This will keep the player table clean and your database normalized.