I have two related entities : Phones and TACs. TACs represent phone models, they are identified by a TAC number which is an 8 digits string. Phones are identified by an IMEI number which is a 15-16 digits string. The first 8 chars of an IMEI number are always a TAC number.
I would like to be able to do something like that so that I can load my phones with their tac data.
schema "tacs" do field(:tac, :string) # exactly 8 chars field(:model_name, :string) [...] end schema "mobile_phones" do field(:imei, :string) # 15 or 16 chars [...] belongs_to(:tacs, Tac, foreign_key: [... the first 8 chars of field :imei ...]) end
I would like to avoid making a DB view. How could I tackle that problem in pure Elixir ?