How to reload a record where the sti_key column changes during an update to a Sequel Single Table Inheritance (STI) row

So lets say I have a table that's setup with Single Table Inheritance:

class Employee < Sequel::Model
  plugin :single_table_inheritance, :kind

  class Staff < self; end
  class Manager < self; end
end

and I create the new record and then subsequently want to update the employee role, like so:

employee = Employee::Manager.create
employee.update(kind: "staff")

The issue I'm having is that employee.class still returns Employee::Manager instead of Employee::Staff and doing a employee.reload results in a Sequel::NoExistingObject: Record not found. Looking at the resulting sql its obvious that's its still trying to find the record using the old type:

SELECT * FROM "employees" WHERE (("employees"."kind" IN ('manager')) AND ("id" = 1)) LIMIT 1

The only way I've been able to get around this is to reload the record from the id:

employee = Employee[employee.id]

Am I missing something or this the only way to refresh the updated record?

Thanks in advance!

Solution

First of all according to your example, you are doing your update in wrong way. It should be like

employee = Employee::Manager.create
employee.update(kind: "Employee::Staff")

because Employee is like a namespace in your example.

And then you can load it class, by calling sti_load on class. there is some variations

em = em.class.sti_load(em) #=> #<Employee::Staff @values={...}>
# or
em = Employee.sti_load(em) #=> #<Employee::Staff @values={...}>
# or
em = Employee::Staff.sti_load(em) #=> #<Employee::Staff @values={...}>