Seeding a user from terminal input

Questions / Help
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1

I am trying to seed a user. I know we can run seeds file by using the following command
mix run priv/repo/seeds.exs

But I would like to pass the following input attrs "first name"this, “last name”, “email” as user input from terminal - like “John”, “Doe”, “john.doe@gmail.com” to

{:ok, user} =
      MyApp.App.register_user%{
        attrs
      })

in seeds.exs.

Any suggestions on how to do this from terminal?

2

You can pass command-line arguments to the script:

mix run priv/repo/seeds.exs foo bar baz

and access them with with System.argv. You might find the OptionParser module useful.

3 Likes
3

@stefanchrobot Thank you. This helped. I have another question that I am currently stuck with. While seeding some of the data are repeated but I have unique_constraint on them. Is there any way to ignore this error and continue with seeding the db?

4

I’d strongly suggest separating one time setup from repeated tasks. I’d even argue the latter are not seeds to begin with.

5

Do you mind elaborating on time setup because my seeds file doesn’t have any time setup. Also if a data already exists, I want it to not create a duplicate, so skip, and proceed to next one.

6

“one time” as in “applied only once when a project is initially deployed/setup”

7

I understand this but in a case where I am manually seeding the db multiple times by running

mix run priv/repo/seeds.exs

how to handle this error or how to skip this error? I am new to Elixir so trying to understand things.

8

The file is just elixir code. You can make it not fail if things already exist (use upserts or check manually if things already exist). To me however seeds are a one time thing for creating a projects baseline db data. It’s not necessarily meant to be applied multiple times.

9

If you’re on PostgreSQL, you can do an upsert with INSERT INTO ... ON CONFLICT ... which is properly supported by Ecto. See the guide in docs.