Fix db:create rake tasks

[rolftimmermans]

When running rake db:create with a default sequel-rails installation (testing this with Rails 5.1.4), the following exception occurs:

rake aborted!
Sequel::DatabaseConnectionError: PG::ConnectionBad: FATAL:  database "my_rails_app_development" does not exist

This happens because by default a connection is made to the configured database. This patch checks to see if we are running inside a Rake tasks and does not automatically connect if we do.

The Rake tasks themselves then call db_for_current_env if they need a connection to the database for the current environment. This only sets up a database connection in Rake tasks as needed.

This solves the exception on db:create for us and others remain working.

[jdanielian]

I'm also running into this issue when trying to upgrade to the latest 1.0 version of the gem. I can't issue a rake sequel:drop , rake sequel:create and have it just work. Now it is stuck with an error saying that the database needs to exist.

I was able to get around these issues by adding test: false as a property to the database.yml. This reverts the connection behavior to sequel 4.x which will NOT attempt to connect to the database by default.

[olivierlacan]

@JonathanTron Could you prioritize merging this as an emergency patch? 1.0 of the gem effectively makes it impossible to use a new Rails app (no schema) at this time because of the attempt to connect prior to db rake tasks.

I've helped document this issue along with @mofmn in this issue.

[olivierlacan]

It might be good to turn this into a method at this point. The conditional is becoming obtuse.

How about extracting a should_connect? method with these two conditions.

Railtie also has a rake hook where you could simply set app.config.sequel[:skip_connect] to true perhaps. I pored over ActiveRecord's railtie to figure out how they're avoiding this issue and couldn't find anything obvious to copy and reuse here.

[olivierlacan]

@rolftimmermans You have duplicated commits in this branch. Could you rebase and merge them so this PR can be merge more easily?

• a656eaf
• cfbf4a9

[JonathanTron]

@rolftimmermans @olivierlacan thanks!

[olivierlacan]

@rolftimmermans @JonathanTron I've grabbed the gem from master and somehow this didn't fix the issue for me. I'll try to step through with pry to see what's happening in the railtie.

[olivierlacan]

Figured it out. @rolftimmermans's patch assumes rake command is invoked when Rails 5 starts to proxy rails db:create to rake db:create and makes direct calls to rake unnecessary.

See Rails Guides:

[rolftimmermans]

Correct, I ran into the same thing.

I now have the equivalent of this code:

if !defined?(Rails::Server) && (Rails.env.development? || Rails.env.test?)
  config.sequel.skip_connect = true
end

That seems to work fine.

So presumably we can use something like this instead of this PR:

if defined?(Rails::Server) || (!Rails.env.development? && !Rails.env.test?)
  ::SequelRails.setup ::Rails.env unless app.config.sequel[:skip_connect]
end

[olivierlacan]

@rolftimmermans See #148. I think we can simply set skip_connect when appropriate instead of wrapping a complex condition around the SequelRails.setup command.

I couldn't think of a reason why we'd have to avoid a connection attempt to the database than when we're trying to create it, and maybe drop it. I could clearly be forgetting something, but for me #148 fixes my db:create issues.