# frozen_string_literal: true# Use this hook to configure devise mailer, warden hooks and so forth.# Many of these configuration options can be set straight in your model.Devise.setupdo|config|Rails.application.credentials[:secret_key_base]# 〜省略〜config.password_length=7..128# 〜省略〜end
bundle install
The dependency tzinfo-data (>= 0) will be unused by any of the platforms Bundler is installing for. Bundler is installing for ruby but the dependency is only for x86-mingw32, x86-mswin32, x64-mingw32, java. To add those platforms to the bundle, run `bundle lock --add-platform x86-mingw32 x86-mswin32 x64-mingw32 java`.
Fetching gem metadata from https://rubygems.org/............
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Bundler could not find compatible versions for gem "bundler":
In Gemfile:
rails (~> 5.1.1) was resolved to 5.1.1, which depends on
bundler (< 2.0, >= 1.3.0)
Current Bundler version:
bundler (2.1.4)
This Gemfile requires a different version of Bundler.
Perhaps you need to update Bundler by running `gem install bundler`?
Could not find gem 'bundler (< 2.0, >= 1.3.0)', which is required by gem 'rails (~> 5.1.1)', in any of the sources.
bundler -v
Bundler version 2.1.4
This confirmation must be received by Slack within 3000 milliseconds of the original request being sent, otherwise a Timeout was reached will be displayed to the user.
defexists?(conditions=:none)ifBase===conditionsraiseArgumentError,<<-MSG.squish
You are passing an instance of ActiveRecord::Base to `exists?`.
Please pass the id of the object by calling `.id`.
MSGendreturnfalseif!conditions||limit_value==0ifeager_loading?relation=apply_join_dependency(eager_loading: false)returnrelation.exists?(conditions)endrelation=construct_relation_for_exists(conditions)skip_query_cache_if_necessary{connection.select_one(relation.arel,"#{name} Exists?")}?true:falseend
Ruby on RailsはRubyで動作するMVCモデルのフレームワークです。
Webアプリケーション開発に向いていて、世の中のあらゆるサービスがこのRuby on Railsでできています。
Railsはオワコンと言われていたりもしますが、僕が会社でRailsのWebアプリ開発をやっていたときに、勉強しやすくて書きやすかったので、とりあえず今回はRailsを使ってみようと思います。
rails serverコマンドでアプリを動かすと、画面にはこんなエラーが出てきます。 ActiveRecord::ConnectionNotEstablished No connection pool with id primary found
なにこれ!?分からん…
ということでググると、RailsのORM機能であるActiveRecordが、sqlite3の新しいバージョンに対応してないことが原因らしい。（参考：ActiveRecord::ConnectionNotEstablished No connection pool）
class CreateHoges < ActiveRecord::Migration[5.2]
def change
create_table :hoges do |t|
t.references :huge
t.text :text
t.timestamps
end
add_foreign_key :hoges, :missname, column: :huge_id # missnameが記述ミス
end
end
そのため、記述を直し改めてマイグレーションファイルを実行したところ以下のエラーが発生しました。
rails aborted!
StandardError: An error has occurred, this and all later migrations canceled:
SQLite3::SQLException: table "hoges" already exists: CREATE TABLE "hoges"
rake aborted!
ActiveRecord::NoEnvironmentInSchemaError:
Environment data not found in the schema. To resolve this issue, run:
bin/rails db:environment:set RAILS_ENV=development
# MySQL. Versions 5.5.8 and up are supported. ## Install the MySQL driver# gem install mysql2## Ensure the MySQL gem is defined in your Gemfile# gem 'mysql2'## And be sure to use new-style password hashing:# https://dev.mysql.com/doc/refman/5.7/en/password-hashing.html#default:&defaultadapter:mysql2encoding:utf8mb4pool:<%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>username:railsuserpassword:******(パスワード)socket:/var/run/mysqld/mysqld.sock
