Unique constraint error while seeding

Questions / Help
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1

Hi,

Unique constraint on owner_name_index.

I would like to create a post in seeds file which belongs to an already created author.

This is the code I have in in my seeds file

defp create_post(owner) do
    attrs =
    Factory.post_factory()
    |> Map.from_struct()
    |> Map.put(:owner_id, owner.id)

    Posts.create_post(attrs)
  end

The factory for post:

def post_factory(attrs \\ %{}) do
    %Post{
      owner: attrs[:owner] || insert(:owner, prefix: "public"),
      title: attrs[:title] || "New title"
    }
  end

When I run seeds file, I get the unique constraint error. Any suggestion on how to avoid this?

2

In post_factory you look if attrs has an owner and if not (when nil), you insert an owner. Because you probably have a unique index on the name of an owner (meaning each owner cannot have the same name), it fails.

When you create your attrs , try passing in the owner like so:

attrs = 
  %{owner: owner} 
  |> Factory.post_factory()
  |> Map.from_struct()

This way uses the existing owner and does not try to create a new one.

OR

  1. you can generate a random name for the owner before you insert.
  2. remove the unique index on name (two or more people having the same name often)
3

@tomkonidas thanks for the quick response. I tried the first solution you gave

attrs = 
  %{owner: owner} 
  |> Factory.post_factory()
  |> Map.from_struct()
  |> Map.put(:owner_id: owner.id)

But I still see the same error. Unfortunately he second suggestion you gave doesn’t seem to work for my requirement.

4

what is owner before you pass it in to the factory?

5

Owner before passing into factory

%MyApp.Blog.Owners.Owner{
  __meta__: #Ecto.Schema.Metadata<:loaded, "public", "owner">,
  id: "1985c756-2592-4332-bb1d-3ed49ca3b35b",
  inserted_at: ~U[2022-04-07 22:02:36.797965Z],
  name: "owner1",
  prefix_name: "mp_$1$q9dv$$mk2$ud1_m0b_z59t$_",
  updated_at: ~U[2022-04-07 22:02:36.807815Z]
}
6

Is there a repo we can see? On the other hand why not use the build function directly? Looking at the ExMachina docs