Relational database design:two 1 to many relations

I have i table users (id,name) and operations (id,date,id_user,id_target_user)

if i didn't have the id_target_user column I'll just make on relation from the users.id to operations.id_user (every user can have multiple several operations) but the problem is the operat开发者_如何学JAVAion maybe related to another user

how to solve this? i can't create 2 relations on the same key can i?

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Yes you can.

• id_user is a foreign key to users.id.

• id_target_user is a foreign key to users.id.

That's all you need.