Create unique integer with ex_machina?

Questions / Help
,
1

I am trying out ex_machina package – I do not see how to create unique integers however. Is this possible? My need is to simulate keys from foreign database. Thanks for advice!

2

There are probably better solutions, but I wonder if you could just use System.unique_integer/1?

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3

I came up with this function:

  def sequence_int(sequence_name, start \\ 0) do
    Agent.get_and_update(ExMachina.Sequence, fn sequences ->
      current_value = Map.get(sequences, sequence_name, start)
      new_sequences = Map.put(sequences, sequence_name, current_value + 1)
      {current_value, new_sequences}
    end)
  end

so I can do

def thing_factory
%{
   foreign_id: sequence_int(:foreign_id, 100)
}
end

I don’t know if this would be a useful feature for others

4

@vrod if you want sequence of integer (as I needed today), you can use this, which will just return the integer value unmodified:

%{
   foreign_id: sequence("foreign_id", & &1)
}
1 Like