Complex Rails associations question

Question

I have three models of concern here:

• User
• Fight
• FightPunches
• Punches

The associations are as follows:

• User has many fights, foreign_key => 'challenger_id or challengee_id'
• Fight belongs to challenger, as User
• Fight belongs to challengee, as User
• Fight has many fight_punches
• FightPunches belongs to fight
• Fight has many punches, through fight_punches
• FightPunch belongs to Punch
• FightPunch belongs to User

Key notes:

• There are three fk's in the FightPunch model: fight_id, punch_id, user_id
• challenger_id and challengee_id reflect the two users who are fighting in the Fight model.

Here is the challenge. I want to create two associations in the Fight model:

1. has_many challenger_punches
2. has_many challengee_punches

The first must grab the records from the Punch model; however, it must only grab those records where Fight.challenger_id = FightPunch.user_id.

Same with #2, but just dealing with the challengee.

Answer 1

belongs_to documentation look under supported options, specifically "foreign_key" and "primary_key"