User:
  columns:
    username: string(255)
    password: string(255)
  relations:
    BankAccounts:
      type: many
      class: BankAccout
      local: id
      foreign: user_id
    Bills:
      type: many
      class: Bill
      local: id
      foreign: user_id


BankAccount:
  columns:
    name: string(255)
    credit: float
    user_id: integer
  relations:
    User:
      local: user_id
      foreign: id
      foreignAlias: BankAccounts