無職になってからやったこと(保険と給付金)

無職になってからのこと書こうと思ったら保険と給付金だけで力尽きました。

ハローワークで求職者登録

だいたいの会社員は雇用主によって雇用保険に加入しており、失業中にはいわゆる失業手当を受給できる。 せっかく保険料払っとるねんから一回ぐらい失業手当もらっとかなあかんなということでハローワーク(公共職業安定所)に通ってる。

ちなみに、ハローワークでいうところの "失業" とは、離職中のひとが "就職しようとする意思といつでも就職できる能力があるにもかかわらず職業に就けず、積極的に求職活動を行っている状態にある" ことをいうそうです。

ところで、失業手当がいくらもらえるのかざっと検索するとだいたい賃金の50～80％ぐらいって出てくるんで、え、そんなもらえたら無職のまま豪遊できてしまうで、と思ったけどそんなうまい話はなかった、基本手当日額には上限が存在していて、僕の場合は基本手当日額7,605円であった。

失業手当（失業保険）のもらい方や条件は？手続きはどうする？もらえる期間・計算方法・金額も解説【社労士監修】 ｜転職ならdoda（デューダ）

https://funjob.jp/shitsugyokeisan/

また、上記基本手当受給資格がある人が給付日数を1/3以上残して安定した職業に就いた場合に残り日数に応じてもらえる再就職手当というのもある。 僕の場合は所定給付日数180日で、再就職手当もらえるぐらいを目処に働くか〜ぐらいの気持ちでいたけど、気づいたらすでに受給日数120日余裕で超えてて再就職手当チャンスのがしてた…。

再就職手当ってどうやってもらうの？条件・計算方法や申請から受給までの流れを解説｜20代・第二新卒・既卒向け転職エージェントのマイナビジョブ20's

これら失業等給付は言われてみればそうかって感じだけど非課税です。

国民年金の免除申請

収入の減少や失業等により国民年金保険料を納めることが経済的に困難な場合、保険料の一部または全額の免除が可能らしいです。

国民年金保険料の免除制度・納付猶予制度｜日本年金機構

とくに経済的にどうということはなかったのだけど、ラーメン屋で麺の量どうしますか(大盛り無料)って言われたときに大盛りでっていう感覚で、とりあえず教えてもらったので免除にしてみた。が、先にハローワークで提出してしまっていた離職票が必要と言われてめちゃくちゃ面倒だった。

もうひとつわかったことは、国民年金の免除申請には離職票が必要だが、ハローワークに行くと離職票の原本を取られてしまうので免除申請ができなくなるということ。あなたで今日3人目ですと言われた。ふつうに考えたらハローワークから行くやろって感じやのに運用がおかしいと思う。

— Ryuta Kamizono (@kamipo) September 7, 2020

なぜふつうに考えたらハローワークから行くやろって感じなのかというと、求職者給付は失業認定が申請日からの起算になるので一日も早く行くインセンティブがあるのに対して、国民年金の切替や免除申請は退職日の翌日から20日の猶予があるから。 https://t.co/TRhErz3I4j

— Ryuta Kamizono (@kamipo) September 8, 2020

面倒だったわりに、免除はしないほうがよかった。まず、年金の保険料は所得控除の対象なのでむしろ払ったほうがよかった。あと、企業型確定拠出年金を個人型のiDeCo口座に移管するのに、免除中は移管の手続きができないということ。というか、新宿区役所でiDeCoのこと聞こうとしたらiDeCoはここじゃないですって対応されたけど、年金保険料の免除を勧めるんやったらiDeCoへの移管ができなくなる副作用が存在するねんから関係なくはないし、そこの対応は改善してほしいと思いました。

ちなみに、年金保険料の納付書はあるので、ワンチャン支払いしたら免除解除されんかなと思ってやってみたけど、年金保険料過誤納額還付・充当通知書が届いて余計面倒なことになっただけなのでおすすめしません。

年金免除申請してると企業年金のiDeCoへの移管ができないからとりあえず年金払ってみたけどやはり免除取消しの申請をせねばならぬのか… pic.twitter.com/XKCCt3dwge

— Ryuta Kamizono (@kamipo) November 23, 2020

健康保険の任意継続

任意継続とは、退職後も前職の健康保険の制度に引き続き加入できる制度です。福利厚生などもあると思うけど、前職が加入してる組合の健康保険を任意継続するか国民健康保険に加入するかは単に保険料の額で決めてよいと言われたので、新宿区役所で保険料がいくらになりそうか聞いてみた。自力で計算してみてもあってるのかどうかわからんかったので。

保険料の計算方法について：新宿区

保険料の減免について：新宿区

https://www.its-kenpo.or.jp/hoken/nini/about/hutan.html

結果、任意継続のほうが保険料は安かったけど、手違いで勧められるままに記入した紙が国民健康保険の加入手続きの用紙で、倍ぐらい保険料が高いほうに加入手続きが完了してしまって泣いた🥲

国保切替か任意継続のどちらか安いほうを選べとの教えを賜っているけど、調べた限り国保の年間保険料を減額する裏技でもない限り僕の推定算定基礎額に保険料率を掛けたらほぼ間違いなく賦課限度額に達するから任意継続より国保切替のほうが安くなるわけがないと思うけどそれならそう教えを賜るはずで謎

— Ryuta Kamizono (@kamipo) September 6, 2020

ふつうの人なら国保のほうが安くなった可能性あることはわかったけど僕の場合はどっちにしろ保険料カンストだったので任意継続にしますって言ったのに手違いで国保に加入の手続きが完了してしまって任意継続した保険証が手に入ったあと喪失の手続きを取らないといけない事態になってしまった…😨

— Ryuta Kamizono (@kamipo) September 7, 2020

保険と給付金以外のこともそのうち書くかもしれません。

Rails 6.1で `created_at > ?` みたいなクエリをいい感じに生成する

Rails 6.1の目玉機能として以下のように書けるwhere拡張を入れてたんですが、いろいろあって6.1からはrevertされてしまいました🥲

posts = Post.order(:id)

posts.where("id >": 9).pluck(:id)  # => [10, 11]
posts.where("id >=": 9).pluck(:id) # => [9, 10, 11]
posts.where("id <": 3).pluck(:id)  # => [1, 2]
posts.where("id <=": 3).pluck(:id) # => [1, 2, 3]

github.com

github.com

なんですが、そんなことで引き下がる僕ではないので、6.1ではpredicate生成に干渉できる拡張ポイントを用意しており、以下のようなコードを適当に読み込まれるところにしたためておけば、いともたやすくwhere拡張を実現することができます。

ActiveSupport.on_load(:active_record) do
  ActiveRecord::PredicateBuilder.prepend Module.new {
    def [](attr_name, value, operator = nil)
      if !operator && attr_name.end_with?(">", ">=", "<", "<=")
        /\A(?<attr_name>.+?)\s*(?<operator>>|>=|<|<=)\z/ =~ attr_name
        operator = OPERATORS[operator]
      end

      super
    end

    OPERATORS = { ">" => :gt, ">=" => :gteq, "<" => :lt, "<=" => :lteq }.freeze
  }
end

ぜひ活用してくださいね😉

activerecord-importを利用して無効なデータを無理やりINSERTする

activerecord-importと:on_duplicate_key_ignoreオプションを組み合わせるとカラム定義の範囲外の値であっても無理やりINSERTすることができます。

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  gem "activerecord", "6.1.0"
  gem "activerecord-import"
  gem "mysql2"
end

require "active_record"
require "logger"

ActiveRecord::Base.establish_connection(adapter: "mysql2", database: "test", username: "root")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :users, force: true do |t|
    t.string :name, index: { unique: true }
    t.decimal :money, precision: 10
  end
end

class User < ActiveRecord::Base
end

attributes = [
  { name: "foo", money: "10000000000" },
  { name: "foo", money: "20000000000" },
]

User.import(attributes, on_duplicate_key_ignore: true)

# User.insert_all(attributes)

puts
puts User.pluck(:money) # => 9999999999
puts

% ruby foo.rb
Fetching gem metadata from https://rubygems.org/..............
Fetching gem metadata from https://rubygems.org/.
Resolving dependencies...
Using concurrent-ruby 1.1.7
Using bundler 2.2.3
Using minitest 5.14.3
Using zeitwerk 2.4.2
Using mysql2 0.5.3
Using i18n 1.8.7
Using tzinfo 2.0.4
Using activesupport 6.1.0
Using activemodel 6.1.0
Using activerecord 6.1.0
Using activerecord-import 1.0.7
-- create_table(:users, {:force=>true})
D, [2021-01-06T14:04:10.296375 #81282] DEBUG -- :    (66.5ms)  DROP TABLE IF EXISTS `users`
D, [2021-01-06T14:04:10.377990 #81282] DEBUG -- :    (80.7ms)  CREATE TABLE `users` (`id` bigint NOT NULL AUTO_INCREMENT PRIMARY KEY, `name` varchar(255), `money` decimal(10), UNIQUE INDEX `index_users_on_name` (`name`))
   -> 0.1967s
D, [2021-01-06T14:04:10.397652 #81282] DEBUG -- :   ActiveRecord::InternalMetadata Load (0.5ms)  SELECT `ar_internal_metadata`.* FROM `ar_internal_metadata` WHERE `ar_internal_metadata`.`key` = 'environment' LIMIT 1
D, [2021-01-06T14:04:10.417055 #81282] DEBUG -- :    (0.3ms)  SELECT @@max_allowed_packet
D, [2021-01-06T14:04:10.424171 #81282] DEBUG -- :   User Create Many (6.8ms)  INSERT IGNORE INTO `users` (`name`,`money`) VALUES ('foo',10000000000),('foo',20000000000)

D, [2021-01-06T14:04:10.428391 #81282] DEBUG -- :    (3.4ms)  SELECT `users`.`money` FROM `users`
9999999999

https://gist.github.com/kamipo/3db82c3bb7cbcbf007b4d4367a5c5227

これはどういう原理かというと、activerecord-importではINSERTしたいけどすでに(ユニークキーが)おなじレコードがあるときはスルーしたい(i.e. on_duplicate_key_ignore)という機能を実現するのにMySQLではINSERT IGNORE構文を使っていて、INSERT IGNOREではINSERT中のすべてのエラーを無視して無効な値は可能ならもっとも近い値に調整してINSERTするという振る舞いをするため、このような挙動を引き起こすことができます。

では、INSERTしたいけどすでに(ユニークキーが)おなじレコードがあるときはスルーしたい、けど無効な値はちゃんとエラーにしてほしいときはどうしたらいいかというと、Rails 6.0から使えるinsert_allというバルクインサート用のAPIを使うことができます。RailsチームではわいがMySQLチョットデキルので、この問題についてはレビューでフィードバックして対処されており安心してご利用になることができます。

github.com

See also

songmu.jp

それでは本年も引き続きよろしくおねがいいたします。

create_or_find_byでcreateもfind_byも失敗させる

Active Recordの話です。

create_or_find_byの実装はcreateしてみてユニーク制約に引っかかったらfind_byしてみるなので、ふつうに考えるとfind_byは成功しそうに見えます。

    def create_or_find_by(attributes, &block)
      transaction(requires_new: true) { create(attributes, &block) }
    rescue ActiveRecord::RecordNotUnique
      find_by!(attributes)
    end

ですが、以下のスクリプトを実行するとcreate_or_find_byはcreateがRecordNotUnique例外を吐いたあと、find_byもRecordNotFound例外を吐いてレコードを見つけられずに死にます。

ちょっと今から会食なので原理は帰ってから書き足しますしばしお待ちを🙇‍♂️

これ時間あったら続き書きたいけどとりいそぎ説明すると、REPEATABLE READでファントムリードを防いでることを利用して失敗させてるからREAD COMMITTEDにしてファントムリードを許すかSERIALIZABLEにするかLocking Readして別トランザクションの更新をブロックすると失敗を防げます。 https://t.co/v4LBhwDWeR

— Ryuta Kamizono (@kamipo) December 20, 2020

https://github.com/rails/rails/blob/3e5d504f7828118928bfcc08e5be284775836794/activerecord/lib/active_record/relation.rb#L208-L212

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  gem "activerecord", "6.1.0"
  gem "mysql2"
end

require "active_record"
require "logger"

ActiveRecord::Base.establish_connection(adapter: "mysql2", database: "test", username: "root")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :users, force: true do |t|
    t.string :name, index: { unique: true }
  end
end

class User < ActiveRecord::Base
end

t = Thread.new do
  sleep 0.1
  User.create!(name: "foo")
end

User.transaction do
  User.find_by!(name: "foo")
rescue ActiveRecord::RecordNotFound
  puts 'User<name: "foo"> not found'

  sleep 0.2

  User.create_or_find_by!(name: "foo").tap do
    puts 'User<name: "foo"> has found or created'
  end
end

t.join

% ruby foo.rb
Fetching gem metadata from https://rubygems.org/.........
Resolving dependencies...
Using concurrent-ruby 1.1.7
Using i18n 1.8.5
Using minitest 5.14.2
Using tzinfo 2.0.3
Using zeitwerk 2.4.2
Using activesupport 6.1.0
Using activemodel 6.1.0
Using activerecord 6.1.0
Using bundler 2.1.4
Using mysql2 0.5.3
-- create_table(:users, {:force=>true})
D, [2020-12-16T18:55:22.915787 #49715] DEBUG -- :    (12.2ms)  DROP TABLE IF EXISTS `users`
D, [2020-12-16T18:55:22.954341 #49715] DEBUG -- :    (37.5ms)  CREATE TABLE `users` (`id` bigint NOT NULL AUTO_INCREMENT PRIMARY KEY, `name` varchar(255), UNIQUE INDEX `index_users_on_name` (`name`))
   -> 0.0754s
D, [2020-12-16T18:55:23.132151 #49715] DEBUG -- :   ActiveRecord::InternalMetadata Load (0.7ms)  SELECT `ar_internal_metadata`.* FROM `ar_internal_metadata` WHERE `ar_internal_metadata`.`key` = 'environment' LIMIT 1
D, [2020-12-16T18:55:23.147310 #49715] DEBUG -- :   TRANSACTION (0.3ms)  BEGIN
D, [2020-12-16T18:55:23.151778 #49715] DEBUG -- :   User Load (0.8ms)  SELECT `users`.* FROM `users` WHERE `users`.`name` = 'foo' LIMIT 1
User<name: "foo"> not found
D, [2020-12-16T18:55:23.283424 #49715] DEBUG -- :   TRANSACTION (0.3ms)  BEGIN
D, [2020-12-16T18:55:23.287159 #49715] DEBUG -- :   User Create (3.5ms)  INSERT INTO `users` (`name`) VALUES ('foo')
D, [2020-12-16T18:55:23.290553 #49715] DEBUG -- :   TRANSACTION (2.8ms)  COMMIT
D, [2020-12-16T18:55:23.359126 #49715] DEBUG -- :   TRANSACTION (0.3ms)  SAVEPOINT active_record_1
D, [2020-12-16T18:55:23.360585 #49715] DEBUG -- :   User Create (1.2ms)  INSERT INTO `users` (`name`) VALUES ('foo')
D, [2020-12-16T18:55:23.361383 #49715] DEBUG -- :   TRANSACTION (0.3ms)  ROLLBACK TO SAVEPOINT active_record_1
D, [2020-12-16T18:55:23.362859 #49715] DEBUG -- :   User Load (0.5ms)  SELECT `users`.* FROM `users` WHERE `users`.`name` = 'foo' LIMIT 1
D, [2020-12-16T18:55:23.363994 #49715] DEBUG -- :   TRANSACTION (0.5ms)  ROLLBACK
Traceback (most recent call last):
    12: from foo.rb:34:in `<main>'
    11: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:209:in `transaction'
    10: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `transaction'
     9: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:308:in `within_new_transaction'
     8: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
     7: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
     6: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
     5: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
     4: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
     3: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:310:in `block in within_new_transaction'
     2: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `block in transaction'
     1: from foo.rb:35:in `block in <main>'
/Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/core.rb:366:in `find_by!': Couldn't find User (ActiveRecord::RecordNotFound)
    87: from foo.rb:34:in `<main>'
    86: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:209:in `transaction'
    85: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `transaction'
    84: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:308:in `within_new_transaction'
    83: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
    82: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
    81: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
    80: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
    79: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
    78: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:310:in `block in within_new_transaction'
    77: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `block in transaction'
    76: from foo.rb:35:in `block in <main>'
    75: from foo.rb:41:in `rescue in block in <main>'
    74: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/querying.rb:22:in `create_or_find_by!'
    73: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:218:in `create_or_find_by!'
    72: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/delegation.rb:108:in `method_missing'
    71: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:406:in `scoping'
    70: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:811:in `_scoping'
    69: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:406:in `block in scoping'
    68: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/delegation.rb:108:in `block in method_missing'
    67: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/delegation.rb:108:in `public_send'
    66: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:209:in `transaction'
    65: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `transaction'
    64: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:308:in `within_new_transaction'
    63: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
    62: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
    61: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
    60: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
    59: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
    58: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:310:in `block in within_new_transaction'
    57: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `block in transaction'
    56: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:218:in `block in create_or_find_by!'
    55: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:114:in `create!'
    54: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:406:in `scoping'
    53: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:811:in `_scoping'
    52: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:406:in `block in scoping'
    51: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:114:in `block in create!'
    50: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:806:in `_create!'
    49: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:55:in `create!'
    48: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/suppressor.rb:48:in `save!'
    47: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:300:in `save!'
    46: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:348:in `with_transaction_returning_status'
    45: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:318:in `transaction'
    44: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:352:in `block in with_transaction_returning_status'
    43: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:300:in `block in save!'
    42: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/validations.rb:53:in `save!'
    41: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:507:in `save!'
    40: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/timestamp.rb:126:in `create_or_update'
    39: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/callbacks.rb:457:in `create_or_update'
    38: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/callbacks.rb:824:in `_run_save_callbacks'
    37: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/callbacks.rb:98:in `run_callbacks'
    36: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/callbacks.rb:457:in `block in create_or_update'
    35: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:900:in `create_or_update'
    34: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/timestamp.rb:108:in `_create_record'
    33: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/callbacks.rb:461:in `_create_record'
    32: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/callbacks.rb:824:in `_run_create_callbacks'
    31: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/callbacks.rb:98:in `run_callbacks'
    30: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/callbacks.rb:461:in `block in _create_record'
    29: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/attribute_methods/dirty.rb:201:in `_create_record'
    28: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/locking/optimistic.rb:79:in `_create_record'
    27: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/counter_cache.rb:166:in `_create_record'
    26: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:929:in `_create_record'
    25: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:375:in `_insert_record'
    24: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/query_cache.rb:22:in `insert'
    23: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:171:in `insert'
    22: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:136:in `exec_insert'
    21: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/mysql/database_statements.rb:55:in `exec_query'
    20: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:215:in `execute_and_free'
    19: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/mysql/database_statements.rb:50:in `execute'
    18: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:204:in `execute'
    17: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_adapter.rb:688:in `log'
    16: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/notifications/instrumenter.rb:24:in `instrument'
    15: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_adapter.rb:696:in `block in log'
    14: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
    13: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
    12: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
    11: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
    10: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
     9: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_adapter.rb:697:in `block (2 levels) in log'
     8: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:205:in `block in execute'
     7: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/dependencies/interlock.rb:47:in `permit_concurrent_loads'
     6: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/share_lock.rb:187:in `yield_shares'
     5: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/dependencies/interlock.rb:48:in `block in permit_concurrent_loads'
     4: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:206:in `block (2 levels) in execute'
     3: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/mysql2-0.5.3/lib/mysql2/client.rb:130:in `query'
     2: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/mysql2-0.5.3/lib/mysql2/client.rb:130:in `handle_interrupt'
     1: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/mysql2-0.5.3/lib/mysql2/client.rb:131:in `block in query'
/Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/mysql2-0.5.3/lib/mysql2/client.rb:131:in `_query': Duplicate entry 'foo' for key 'users.index_users_on_name' (Mysql2::Error)
    87: from foo.rb:34:in `<main>'
    86: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:209:in `transaction'
    85: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `transaction'
    84: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:308:in `within_new_transaction'
    83: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
    82: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
    81: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
    80: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
    79: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
    78: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:310:in `block in within_new_transaction'
    77: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `block in transaction'
    76: from foo.rb:35:in `block in <main>'
    75: from foo.rb:41:in `rescue in block in <main>'
    74: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/querying.rb:22:in `create_or_find_by!'
    73: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:218:in `create_or_find_by!'
    72: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/delegation.rb:108:in `method_missing'
    71: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:406:in `scoping'
    70: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:811:in `_scoping'
    69: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:406:in `block in scoping'
    68: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/delegation.rb:108:in `block in method_missing'
    67: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/delegation.rb:108:in `public_send'
    66: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:209:in `transaction'
    65: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `transaction'
    64: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:308:in `within_new_transaction'
    63: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
    62: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
    61: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
    60: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
    59: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
    58: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:310:in `block in within_new_transaction'
    57: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `block in transaction'
    56: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:218:in `block in create_or_find_by!'
    55: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:114:in `create!'
    54: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:406:in `scoping'
    53: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:811:in `_scoping'
    52: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:406:in `block in scoping'
    51: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:114:in `block in create!'
    50: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:806:in `_create!'
    49: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:55:in `create!'
    48: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/suppressor.rb:48:in `save!'
    47: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:300:in `save!'
    46: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:348:in `with_transaction_returning_status'
    45: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:318:in `transaction'
    44: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:352:in `block in with_transaction_returning_status'
    43: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:300:in `block in save!'
    42: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/validations.rb:53:in `save!'
    41: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:507:in `save!'
    40: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/timestamp.rb:126:in `create_or_update'
    39: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/callbacks.rb:457:in `create_or_update'
    38: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/callbacks.rb:824:in `_run_save_callbacks'
    37: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/callbacks.rb:98:in `run_callbacks'
    36: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/callbacks.rb:457:in `block in create_or_update'
    35: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:900:in `create_or_update'
    34: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/timestamp.rb:108:in `_create_record'
    33: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/callbacks.rb:461:in `_create_record'
    32: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/callbacks.rb:824:in `_run_create_callbacks'
    31: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/callbacks.rb:98:in `run_callbacks'
    30: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/callbacks.rb:461:in `block in _create_record'
    29: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/attribute_methods/dirty.rb:201:in `_create_record'
    28: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/locking/optimistic.rb:79:in `_create_record'
    27: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/counter_cache.rb:166:in `_create_record'
    26: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:929:in `_create_record'
    25: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/persistence.rb:375:in `_insert_record'
    24: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/query_cache.rb:22:in `insert'
    23: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:171:in `insert'
    22: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:136:in `exec_insert'
    21: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/mysql/database_statements.rb:55:in `exec_query'
    20: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:215:in `execute_and_free'
    19: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/mysql/database_statements.rb:50:in `execute'
    18: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:204:in `execute'
    17: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_adapter.rb:688:in `log'
    16: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/notifications/instrumenter.rb:24:in `instrument'
    15: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_adapter.rb:696:in `block in log'
    14: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
    13: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
    12: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
    11: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
    10: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
     9: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_adapter.rb:697:in `block (2 levels) in log'
     8: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:205:in `block in execute'
     7: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/dependencies/interlock.rb:47:in `permit_concurrent_loads'
     6: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/share_lock.rb:187:in `yield_shares'
     5: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/dependencies/interlock.rb:48:in `block in permit_concurrent_loads'
     4: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:206:in `block (2 levels) in execute'
     3: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/mysql2-0.5.3/lib/mysql2/client.rb:130:in `query'
     2: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/mysql2-0.5.3/lib/mysql2/client.rb:130:in `handle_interrupt'
     1: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/mysql2-0.5.3/lib/mysql2/client.rb:131:in `block in query'
/Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/mysql2-0.5.3/lib/mysql2/client.rb:131:in `_query': Mysql2::Error: Duplicate entry 'foo' for key 'users.index_users_on_name' (ActiveRecord::RecordNotUnique)
    18: from foo.rb:34:in `<main>'
    17: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/transactions.rb:209:in `transaction'
    16: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `transaction'
    15: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:308:in `within_new_transaction'
    14: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
    13: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
    12: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `block in synchronize'
    11: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:25:in `handle_interrupt'
    10: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activesupport-6.1.0/lib/active_support/concurrency/load_interlock_aware_monitor.rb:26:in `block (2 levels) in synchronize'
     9: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/transaction.rb:310:in `block in within_new_transaction'
     8: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/connection_adapters/abstract/database_statements.rb:320:in `block in transaction'
     7: from foo.rb:35:in `block in <main>'
     6: from foo.rb:41:in `rescue in block in <main>'
     5: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/querying.rb:22:in `create_or_find_by!'
     4: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:217:in `create_or_find_by!'
     3: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation.rb:220:in `rescue in create_or_find_by!'
     2: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/finder_methods.rb:87:in `find_by!'
     1: from /Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/finder_methods.rb:104:in `take!'
/Users/kamipo/.rbenv/versions/2.7.1/lib/ruby/gems/2.7.0/gems/activerecord-6.1.0/lib/active_record/relation/finder_methods.rb:354:in `raise_record_not_found_exception!': Couldn't find User with [WHERE `users`.`name` = ?] (ActiveRecord::RecordNotFound)

https://gist.github.com/kamipo/480f9e6fb61bef0f36b1edbccfd30f66

SELECT ... FOR UPDATE同士でデッドロックさせる

最近SELECT ... FOR UPDATEでデッドロックする話を何度かしたので。

前職のときにUPDATE同士がデッドロックしてたときに、SELECT ... FOR UPDATEで排他ロックを取ってからUPDATEしてデッドロックを防ぎますってPRをレビューしてたときのことで、複数レコードの排他ロックは一瞬ですべてのレコードのロックを取れるわけではなく、ロックを取る順番が揃っていないと簡単にデッドロックしますよという話です。

https://gist.github.com/kamipo/0bb4e37d58ba18a8cefb8aa02f778231

# frozen_string_literal: true

require "mysql2"

def client
  Mysql2::Client.new(
    host: "localhost",
    username: "root",
    database: "test",
  )
end

c1 = client
c2 = client

c1.query("DROP TABLE IF EXISTS `user_tables`")
c1.query <<-SQL
CREATE TABLE `user_tables` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `index_user_tables_on_name` (`name`)
)
SQL

1000.downto(1) do |i|
  c1.query("INSERT INTO `user_tables` (`name`) VALUES ('p#{i}')")
end

t = Thread.new do
  100.times do |j|
    c2.query("BEGIN")
    #puts "c2 locking:#{j}"
    c2.query("SELECT 1 FROM `user_tables` FORCE INDEX(index_user_tables_on_name) WHERE `name` IN (#{1000.downto(1).map{|i|"'p#{i}'"}.join(",")}) FOR UPDATE")
    #puts "c2 locked:#{j}"
    c2.query("COMMIT")
  end
end

100.times do |j|
  c1.query("BEGIN")
  #puts "c1 locking:#{j}"
  c1.query("SELECT 1 FROM `user_tables` FORCE INDEX(PRIMARY) WHERE `id` IN (#{1.upto(1000).to_a.join(",")}) FOR UPDATE")
  #puts "c1 locked:#{j}"
  c1.query("COMMIT")
end

t.join

% be ruby lock.rb
/Users/kamipo/.rbenv/versions/2.7.0-dev/lib/ruby/gems/2.7.0/gems/bundler-1.17.3/lib/bundler/rubygems_integration.rb:200: warning: constant Gem::ConfigMap is deprecated
/Users/kamipo/.rbenv/versions/2.7.0-dev/lib/ruby/gems/2.7.0/gems/bundler-1.17.3/lib/bundler/rubygems_integration.rb:200: warning: constant Gem::ConfigMap is deprecated
#<Thread:0x00007fa6099b38c0@lock.rb:30 run> terminated with exception (report_on_exception is true):
Traceback (most recent call last):
    6: from lock.rb:31:in `block in <main>'
    5: from lock.rb:31:in `times'
    4: from lock.rb:34:in `block (2 levels) in <main>'
    3: from /Users/kamipo/src/github.com/brianmario/mysql2/lib/mysql2/client.rb:130:in `query'
    2: from /Users/kamipo/src/github.com/brianmario/mysql2/lib/mysql2/client.rb:130:in `handle_interrupt'
    1: from /Users/kamipo/src/github.com/brianmario/mysql2/lib/mysql2/client.rb:138:in `block in query'
/Users/kamipo/src/github.com/brianmario/mysql2/lib/mysql2/client.rb:138:in `_query': Deadlock found when trying to get lock; try restarting transaction (Mysql2::Error)
Traceback (most recent call last):
    6: from lock.rb:31:in `block in <main>'
    5: from lock.rb:31:in `times'
    4: from lock.rb:34:in `block (2 levels) in <main>'
    3: from /Users/kamipo/src/github.com/brianmario/mysql2/lib/mysql2/client.rb:130:in `query'
    2: from /Users/kamipo/src/github.com/brianmario/mysql2/lib/mysql2/client.rb:130:in `handle_interrupt'
    1: from /Users/kamipo/src/github.com/brianmario/mysql2/lib/mysql2/client.rb:138:in `block in query'
/Users/kamipo/src/github.com/brianmario/mysql2/lib/mysql2/client.rb:138:in `_query': Deadlock found when trying to get lock; try restarting transaction (Mysql2::Error)

これはどういう原理でデッドロックさせているかというと、プライマリキーとセカンダリキーで意図的に並び順が異なるようなデータを生成して、プライマリキーを使う実行計画のSELECT ... FOR UPDATEとセカンダリキーを使う実行計画のSELECT ... FOR UPDATEが真逆の順序でレコードのロックを取るように仕向けてデッドロックを引き起こさせています。

このように、複数レコードのロックは一瞬で同時に起きるわけではなく、順番に起きて途中の状態(ロックが取り終わったレコードとこれからロックを取るつもりのレコードがある状態)が存在するので、ロックを取る順番が一意になるようにクエリや実行計画を揃えるというのがこの手の問題に対する一般的な対処法になります。

ロックを取る順番って見えづらいので問題に気づきづらいですよね、かくいう僕も眼の良さを活かして気合いで対処してるので、なんかいい方法あったら教えてください。

ツイッターで見つけて直したActiveRecordの問題さらに3つ

ツイッターで見つけて直したActiveRecordの問題3つ - かみぽわーるの続き。

• where(id: ..1) ("id" <= 1)をnotしたら"id" > 1になってほしい

今のmasterで試してみたのですが、SELECT "users".* FROM "users" WHERE NOT ("users"."id" <= 1) になるようです。 https://t.co/pQh4h9g0MP

— 神速 (@sinsoku_listy) August 3, 2019

github.com

• association先のカラムをpluckしたときもちゃんとtype castされてほしい

対応ありがとうございます！
制限があるとはいえ、定義ではなく呼び出し側で解決を図れるのは嬉しいです。

ちなみに association の情報を与えてあげるようなアプローチは既に検討済みですか？例えばこういう…
User.joins(:association).pluck(association: :column_name)

— _h_s_ (@_h_s_) May 14, 2020

github.com

• rewhereでちゃんとテーブルを考慮してwhere句を上書きしてほしい

rewhere(except) がテーブルを考慮するようになればだいぶ楽になるなあ

— バンビちゃん@実際存在しません (@pink_bangbi) November 29, 2019

ActiveRecord むずかしいにゃんねえ
【Ruby on Rails Advent Calendar 2019】ActiveRecord で後から where クエリを上書きする【2日目】 - Secret Garden(Instrumental) https://t.co/ojNO3TZrBA

— バンビちゃん@実際存在しません (@pink_bangbi) December 1, 2019

github.com

ツイッターで見つけて直したActiveRecordの問題3つ

Rails Advent Calendar 2020の3日目です。

時間がないのでとりいそぎ3つだけ。

• enum state: {active: 0, inactive: 1}とかした時に、typecast前の0とか1を取りたい

ActiveRecord::Enumってstate: {active: 0, inactive: 1}とかした時に、typecast前の0とか1を取る場合、read_attribute_before_type_castを使うしかないのか？

— アルフォートおじさん (@joker1007) October 21, 2020

github.com

• belongs_to :author, class_name: 'User'したときにleft_joins(:author).where("author.id": nil)とか書きたい

これすると、joins(:author).where(users: { id: nil }) みたいに書く必要もあったり、各所でオプションが必要になったりで、個人的にはあまり好きじゃない。

— 神速 (@sinsoku_listy) June 4, 2020

github.com

• attributeでDBの型情報を保ったままdefault値だけ定義したい

ActiveRecordでDBから動的にprecisionを取得しつつ
attribute(..., default: '') でデフォルト値を定義する方法、無いな🙄

誰もそんなことをする人おらんもんな。
どうしたもんかねぇ。

— いっくん (@alpaca_tc) July 7, 2020

github.com