ExMachina and many_to_many problems

Questions / Help
,
1

I have a problem with ExMachina, where I have company <-> role_relation <-> user many_to_many relationsship between users and companies.

the role relation table has a NOT NULL constraint on the key role_name, company_id and user_id, the only columns other than timestamps.

I have factories like this

def supplier_company_factory do
  %Company{
    name: sequence(:name, &"Company-#{&1}"),
    contact_name: sequence(:contact_name, &"test-#{&1}"),
    users:
      build_pair(:user,
        roles: [build(:role_relation, role_name: "supplier")]
      )
  }
end

def user_factory do
  %User{
    email: sequence(:email, &"USER-#{&1}@EXAMPLE.COM"),
    first_name: sequence(:first_name, &"test-#{&1}"),
    last_name: sequence(:first_name, &"user-#{&1}"),
    office_phone: "office phone",
    mobile_phone: "mobile phone",
    details: %{
      settings: %{use_local_timezone: true}
    }
  }
end

def role_relation_factory do
  %RoleRelation{
    role_name: "auction_manager"
  }
end

if i then write insert(:supplier_company) I get this error:

** (Postgrex.Error) ERROR 23502 (not_null_violation) null value in column "company_id" of relation "role_relations" violates not-null constraint

         table: role_relations
         column: company_id

   Failing row contains (supplier, 1, null, 2025-02-26 08:50:42, 2025-02-26 08:50:42).

You can clearly see in the insert query, that the company_id is NULL.

Extra info

role_relation schema

@primary_key false
schema "role_relations" do
  field(:role_name, :string)
  belongs_to(:user, User, primary_key: true)
  belongs_to(:company, Company, primary_key: true)

  timestamps()
end

company schema

schema "companies" do
  [fields ...]
  many_to_many(
      :users,
      User,
      join_through: RoleRelation,
      join_keys: [company_id: :id, user_id: :id],
      on_replace: :delete,
      on_delete: :delete_all
    )
end

user schema

schema "users" do
  [fields...]
 many_to_many(
      :companies,
      Company,
      join_through: RoleRelation,
      join_keys: [user_id: :id, company_id: :id],
      on_replace: :delete,
      on_delete: :delete_all
    )
end

Am I missing something here?