Expose Structure.dump_cmd/3

[maennchen]

Follow up from #419 (comment)

[maennchen]

@josevalim I did not change anything with how the migrations work. I just took this as an example since I knew how to call it from the PR before.

[josevalim]

Thank you! What about tds?

[maennchen]

@josevalim Tds does not implement Ecto.Adapter.Structure

[maennchen]

(It also does not look as if there's a management CLI: https://dba.stackexchange.com/questions/273158/how-can-i-dump-the-schema-of-a-sql-server-database-on-linux)

EDIT: We could implement it using SQLpackage.exe, but that should be a separate issue / PR I think.

[josevalim]

Sorry, there is one last nitpick. Generally speaking, we want to make the adapter behaviour as small as possible. This means we should not receive both Repo and Config. Also, other functions in this module receive the config as the last opts, so I propose for this to be:

Suggested change

	@callback dump_cmd(
	repo_or_config :: module() | Keyword.t(),
	args :: [String.t()],
	opts :: Keyword.t()
	) :: {output :: Collectable.t(), exit_status :: non_neg_integer()}
	@callback dump_cmd(
	args :: [String.t()],
	opts :: Keyword.t(),
	config :: Keyword.t()
	) :: {output :: Collectable.t(), exit_status :: non_neg_integer()}

And then if you want a more convenient API which is dump_cmd(repo | config, args, opts), we can add it to Ecto.Adapters.SQL, but I think we can skip it for now and the low-level one is fine. :)

[josevalim]

In other words, let's just change the signature here, update the code, and ship it!!!

[maennchen]

@josevalim Ok, I'm on it 👍

[maennchen]

@josevalim Changed

[josevalim]

💚 💙 💜 💛 ❤️

[maennchen]

@josevalim Would you like me to create an issue for TDS / SqlPackage.exe support?