Use more than one database in Sequel application

Question

I am using sequel to query information from different databases. Using the following code

Sequel.connect(mmt018_db_connection_settings) do |db|
  class ResultPlacementAssign < Sequel::Model(db[:result_placement_assign]); end
  # do something with 'ResultPlacementAssign'
end

Sequel.connect(mmt024_db_connection_settings) do |db|
  class PlatineMass < Sequel::Model(db[:platine_mass]); end
  # do something with 'PlatineMass'
end

works great. But if I try to put my model definitions in separate files in order to require them when needed, it seems that only the first database connection works. So changing the above code to

Sequel.connect(mmt018_db_connection_settings) do |db|
  require File.join(__dir__, 'models', 'm_mt_018', 'ResultPlacementAssign.rb')
  # do something with 'ResultPlacementAssign'
end

Sequel.connect(mmt024_db_connection_settings) do |db|
  require File.join(__dir__, 'models', 'm_mt_024', 'PlatineMass.rb')
  # do something with 'PlatineMass'
end

using the model definitions

class ResultPlacementAssign < Sequel::Model(:result_placement_assign)
end

and

class PlatineMass < Sequel::Model(:platine_mass)
end

does not work.
It tells me that platine_mass does not exist in database, because it's still using the first connection. Am I missing something, or is there really no way to tell the model definition which database connection to use, if it's defined in a separate file.

Answer 1

You can tell Sequel which Database to use for a given model by passing a Database or Dataset argument to Sequel::Model(). In general, you should assign Database objects to constants:

DB1 = Sequel.connect(mmt018_db_connection_settings)
DB2 = Sequel.connect(mmt024_db_connection_settings)
class ResultPlacementAssign < Sequel::Model(DB1[:result_placement_assign]); end
class PlatineMass < Sequel::Model(DB2[:platine_mass]); end