Print the record count using Phoenix/Ecto from the terminal

Question

On the Rails app, we can print the record count of a database table by a command like this:

rails r "puts User.count"

With my knowledge, if we want the same thing on the Phoenix/Ecto environment, we should run such a command:

mix run -e "IO.puts SampleApp.Repo.aggregate(SampleApp.User, :count, :id)"

That is OK, but is too lengthy for a daily usage. Is there any shorter way?

Answer 1

Out of the box, there is not.

You can however define a function in the SampleApp module to make it shorter. Something like this should do the trick (I haven't tested this):

defmodule SampleApp do
  ...

  def count(model)
    IO.puts Repo.aggregate(model, :count, :id)
  end
end

Then you can do this:

mix run -e "SampleApp.count(SampleApp.User)"