@startuml

hide circle
skinparam linetype ortho

entity users_telegram {
  id : int <<PK>>
  first_name : longtext
  last_name : longtext null
  username : longtext null
  phone_number : longtext null
  last_update : datetime
  --
}

entity users {
  id : binary(40) <<PK>>
  telegram : int <<FK>>
  --
  * telegram = users_telegram.id
    on update cascade
    on delete cascade
}
users ||-o| users_telegram

entity credit_wallet {
  id : binary(40) <<PK>>
  owner : binary(40) <<FK>>
  balance : int
  --
  * owner = users.id
    on update cascade
    on delete cascade
}
users ||--|| credit_wallet

@enduml