{"id":26168,"date":"2021-08-01T08:08:09","date_gmt":"1970-01-01T00:00:00","guid":{"rendered":"http:\/\/www.sejuku.net\/blog\/?p=26168"},"modified":"2024-05-06T11:43:39","modified_gmt":"2024-05-06T02:43:39","slug":"%e3%80%90rails%e5%85%a5%e9%96%80%e3%80%91includes%e3%81%ae%e4%bd%bf%e3%81%84%e6%96%b9%e3%81%be%e3%81%a8%e3%82%81","status":"publish","type":"post","link":"https:\/\/www.sejuku.net\/blog\/26168","title":{"rendered":"\u3010Rails\u5165\u9580\u3011\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u60aa\u3044\u306a\u3089includes\/order\u3092\u691c\u8a0e\u3057\u3088\u3046"},"content":{"rendered":"

\u307f\u306a\u3055\u3093\u306f\u30012\u3064\u306e\u95a2\u9023\u4ed8\u3051\u3089\u308c\u305f\u30c6\u30fc\u30d6\u30eb\u3092\u6271\u3063\u3066\u3044\u308b\u3068\u304d\u306b\u3001\u3069\u306e\u3088\u3046\u306b\u5024\u3092\u53d6\u308a\u51fa\u3057\u3066\u3044\u307e\u3059\u304b\uff1f<\/strong><\/span><\/p>\n

\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u6c17\u306b\u305b\u305a\u3001all<\/strong><\/span>\u3084join<\/strong><\/span>\u3092\u4f7f\u3063\u3066\u3001N+1\u554f\u984c<\/strong><\/span>\u3092\u767a\u751f\u3055\u305b\u3066\u3044\u307e\u305b\u3093\u304b\uff1f<\/p>\n

\u305d\u308c\u3068\u3082\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u6c17\u306b\u3057\u3066\u3001includes<\/strong><\/span>\u3084preload<\/strong><\/span>\u3001eager_load<\/strong><\/span>\u3092\u4f7f\u3063\u3066\u3044\u307e\u3059\u304b\uff1f<\/p>\n

\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u4e0a\u3052\u308b\u305f\u3081\u306e1\u3064\u306e\u89e3\u6cd5\u3067\u3042\u308bincludes\u3092\u53d6\u308a\u4e0a\u3052\u3001\u4ee5\u4e0b\u306e\u5185\u5bb9\u3092\u8aac\u660e\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n

\u30fbN+1\u554f\u984c\u3068\u306f
\n\u30fb2\u3064\u306e\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u30c7\u30fc\u30bf\u3092\u53d6\u5f97\u3059\u308b\u65b9\u6cd5
\n\u30fb\u30cd\u30b9\u30c8\u3055\u308c\u305f\u8907\u6570\u306e\u30c6\u30fc\u30d6\u30eb\u304b\u3089includes\u3067\u30c7\u30fc\u30bf\u3092\u4e00\u62ec\u53d6\u5f97\u3059\u308b\u65b9\u6cd5\n<\/div>\n

\u3055\u3089\u306b\u3001\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u30c7\u30fc\u30bf\u3092\u4e26\u3079\u66ff\u3048\u305f\u72b6\u614b\u3067\u53d6\u5f97\u3059\u308b\u305f\u3081\u306eorder<\/strong><\/span>\u3092\u53d6\u308a\u4e0a\u3052\u3001\u4ee5\u4e0b\u306e\u5185\u5bb9\u3092\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n

\u30fb\u30c7\u30fc\u30bf\u3092\u4e26\u3079\u66ff\u3048\u308b\u65b9\u6cd5
\n\u30fb\u8907\u6570\u306e\u30ab\u30e9\u30e0\u3092\u4f7f\u3063\u3066\u4e26\u3079\u66ff\u3048\u308b\u65b9\u6cd5
\n\u30fbreorder\u306e\u4f7f\u3044\u3069\u3053\u308d
\n\u30fborder_as_specified gem\u3092\u4f7f\u3063\u3066\u9806\u756a\u30921\u30641\u3064\u6307\u5b9a\u3057\u3066\u30c7\u30fc\u30bf\u3092\u53d6\u5f97\u3059\u308b\u65b9\u6cd5\n<\/div>\n

\u30c7\u30fc\u30bf\u304c\u5c11\u306a\u3044\u3046\u3061\u306f\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u554f\u984c\u3092\u611f\u3058\u306a\u304f\u3066\u3082\u3001\u30c7\u30fc\u30bf\u304c\u591a\u304f\u306a\u3063\u305f\u3068\u304d\u306e\u3053\u3068\u3092\u8003\u3048\u3066\u3001\u4eca\u306e\u3046\u3061\u306bN+1\u554f\u984c\u3092\u89e3\u6c7a\u3057\u3066\u304a\u304d\u307e\u3057\u3087\u3046\uff01<\/strong><\/span><\/p>\n

\u307e\u305f\u3001\u30c7\u30fc\u30bf\u3092\u53d6\u5f97\u3057\u3066\u304b\u3089Rails\u3067\u4e26\u3079\u66ff\u3048\u308b\u3088\u308a\u3082\u3001\u30c7\u30fc\u30bf\u3092\u4e26\u3079\u66ff\u3048\u305f\u72b6\u614b\u3067\u53d6\u5f97\u3057\u305f\u307b\u3046\u304c\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u7684\u306b\u3082\u6709\u5229\u3067\u3059\u3002<\/p>\n

\u3053\u306e\u8a18\u4e8b\u3067\u3001order\u306e\u4f7f\u3044\u65b9\u3082\u3042\u308f\u305b\u3066\u30de\u30b9\u30bf\u30fc\u3057\u3066\u3057\u307e\u3044\u307e\u3057\u3087\u3046\u3002<\/strong><\/span><\/p>\n

\u3067\u306f\u3001\u9806\u756a\u306b\u8aac\u660e\u3057\u3066\u3044\u304d\u307e\u3059\u306d\u3002<\/p>\n

includes\u3068\u306f\u3001N+1\u554f\u984c\u3068\u306f<\/h2>\n

includes\u306f\u3001\u95a2\u9023\u4ed8\u3051\u3089\u308c\u305f2\u3064\u306e\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u53c2\u7167\u3059\u308b\u30e1\u30bd\u30c3\u30c9\u3067\u3059\u3002<\/p>\n

\u4e3b\u306bN+1\u554f\u984c\u3092\u89e3\u6c7a\u3059\u308b\u305f\u3081\u306b\u5229\u7528\u3055\u308c\u307e\u3059\u3002<\/p>\n

N+1\u554f\u984c\u306b\u3064\u3044\u3066\u306f\u3001\u5177\u4f53\u4f8b\u3092\u898b\u308b\u3068\u89e3\u308a\u3084\u3059\u3044\u3068\u601d\u3044\u307e\u3059\u306e\u3067\u3001\u65e9\u901f\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n

\u4ee5\u4e0b\u306e\u3088\u3046\u306a2\u3064\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u4f5c\u6210\u3057\u307e\u3059\u3002<\/p>\n\n\n\n\n\t\n\n\t\n\t
\u30c6\u30fc\u30d6\u30eb<\/th>\u30ab\u30e9\u30e0<\/th>\n<\/tr>\n<\/thead>\n
User\u30c6\u30fc\u30d6\u30eb<\/td>name
\nposts\uff08has_many\uff09<\/td>\n<\/tr>\n
Post\u30c6\u30fc\u30d6\u30eb<\/td>user_id\uff08belongs_to\uff09
\ntitle
\nmonth<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n

\u305d\u3057\u3066\u3001User\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u3001Post\u30c6\u30fc\u30d6\u30eb\u306etitle\u3092\u53c2\u7167\u3059\u308b\u65b9\u6cd5\u3092\u8003\u3048\u307e\u3059\u3002<\/p>\n

\u4e00\u756a\u624b\u3063\u53d6\u308a\u65e9\u3044\u306e\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30b3\u30fc\u30c9\u3067\u3059\u306d\u3002<\/p>\n

User.all.each { |user| user.posts.each{ |post| puts \"#{user.name} \/ #{post.title}\"} }<\/pre>\n
\u3057\u304b\u3057\u3001\u3053\u308c\u3067\u306f\u3001\u30c7\u30fc\u30bf\u6570\u304c\u591a\u304f\u306a\u3063\u305f\u3068\u304d\u306b\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u554f\u984c\u304c\u767a\u751f\u3057\u3066\u3057\u307e\u3044\u307e\u3059\u3002<\/p>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n
  User Load (0.2ms)  SELECT \"users\".* FROM \"users\"\r\n  Post Load (0.2ms)  SELECT \"posts\".* FROM \"posts\" WHERE \"posts\".\"user_id\" = ?  [[\"user_id\", 1]]\r\n\u5c71\u7530\u592a\u90ce \/ \u5148\u65e5\u306e\u65c5\u884c\u3067\u306e\u8a71\r\n  Post Load (0.1ms)  SELECT \"posts\".* FROM \"posts\" WHERE \"posts\".\"user_id\" = ?  [[\"user_id\", 2]]\r\n\u9577\u702c\u6765 \/ \u6700\u8fd1\u5c11\u3057\u6c17\u306b\u306a\u3063\u305f\u3053\u3068\r\n  Post Load (0.1ms)  SELECT \"posts\".* FROM \"posts\" WHERE \"posts\".\"user_id\" = ?  [[\"user_id\", 3]]\r\n\u7acb\u5ddd\u88d5\u7f8e \/ \u6628\u65e5\u306e\u51fa\u6765\u4e8b\r\n\u7acb\u5ddd\u88d5\u7f8e \/ \u5c71\u767b\u308a\u306b\u884c\u304d\u307e\u3057\u305f\r\n\u7acb\u5ddd\u88d5\u7f8e \/ Ruby on Rails\u306e\u65e5\r\n  Post Load (0.1ms)  SELECT \"posts\".* FROM \"posts\" WHERE \"posts\".\"user_id\" = ?  [[\"user_id\", 4]]\r\n\u524d\u7530\u9054\u90ce \/ \u53cb\u4eba\u304c\u7d50\u5a5a\u3057\u307e\u3057\u305f\r\n\u524d\u7530\u9054\u90ce \/ \u30e9\u30f3\u30cb\u30f3\u30b0\u306e\u30b3\u30c4\r\n  Post Load (0.1ms)  SELECT \"posts\".* FROM \"posts\" WHERE \"posts\".\"user_id\" = ?  [[\"user_id\", 5]]\r\n\u7d30\u5ddd\u4fee\u4e8c \/ \u697d\u3057\u3044\u4f11\u65e5\u306e\u904e\u3054\u3057\u65b9\r\n  Post Load (0.1ms)  SELECT \"posts\".* FROM \"posts\" WHERE \"posts\".\"user_id\" = ?  [[\"user_id\", 6]]\r\n+----+----------+-------------------------+-------------------------+\r\n| id | name     | created_at              | updated_at              |\r\n+----+----------+-------------------------+-------------------------+\r\n| 1  | \u5c71\u7530\u592a\u90ce | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 2  | \u9577\u702c\u6765   | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 3  | \u7acb\u5ddd\u88d5\u7f8e | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 4  | \u524d\u7530\u9054\u90ce | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 5  | \u7d30\u5ddd\u4fee\u4e8c | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 6  | \u6728\u6751\u62d3\u78e8 | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n+----+----------+-------------------------+-------------------------+\r\n6 rows in set<\/pre>\n
\u5b9f\u884c\u7d50\u679c\u306e\u898b\u304b\u305f\u3092\u8aac\u660e\u3057\u3066\u304a\u304d\u307e\u3059\u3002<\/p>\n
\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306eUser\u30c6\u30fc\u30d6\u30eb\u3092\u8aad\u307f\u8fbc\u3093\u3060\u30bf\u30a4\u30df\u30f3\u30b0\u3067\u300cUser Load (0.1ms)…\u300d<\/strong><\/span>\u3068\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n
\u540c\u69d8\u306bPost\u30c6\u30fc\u30d6\u30eb\u3092\u8aad\u307f\u8fbc\u3093\u3060\u3068\u304d\u306b\u300cPost Load (0.1ms)…\u300d<\/strong><\/span>\u3068\u8868\u793a\u3055\u308c\u308b\u306e\u3067\u3059\u304c\u3001\u3053\u308c\u304c6\u56de\u8868\u793a\u3055\u308c\u3066\u3044\u307e\u3059\u306d\u3002<\/p>\n
\u3064\u307e\u308a\u30016\u540d\u5206\u306epost.title\u3092\u53d6\u5f97\u3059\u308b\u305f\u3081\u306b\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306b6\u56de\u30a2\u30af\u30bb\u30b9\u3057\u3066\u3044\u308b\u30ef\u30b1\u3067\u3059\u304c\u3001includes\u3092\u4f7f\u3046\u3068\u3053\u308c\u30921\u56de\u306b\u524a\u6e1b\u3067\u304d\u307e\u3059\u3002<\/p>\n
1\u56de\u306e\u30a2\u30af\u30bb\u30b9\u3067\u89e3\u6c7a\u3067\u304d\u308b\u3082\u306e\u3092\u30016\u56de\u3082\u30a2\u30af\u30bb\u30b9\u3057\u3066\u3044\u308b\u306e\u3067\u554f\u984c\u3068\u3055\u308c\u3066\u3044\u3066\u3001\u4e00\u822c\u7684\u306bN+1\u554f\u984c<\/strong><\/span>\u304c\u767a\u751f\u3057\u3066\u3044\u308b\u3068\u8a00\u3044\u307e\u3059\u3002<\/p>\n
\u5177\u4f53\u7684\u306b\u306f\u3001\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3067Post\u30c6\u30fc\u30d6\u30eb\u306b\u30a2\u30af\u30bb\u30b9\u3059\u308b\u56de\u6570\u30921\u56de\u306b\u6e1b\u3089\u305b\u307e\u3059\u3002<\/p>\n
User.includes(:posts).each { |user| user.posts.each{ |post| puts \"#{user.name} \/ #{post.title}\"} }<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n
  User Load (0.1ms)  SELECT \"users\".* FROM \"users\"\r\n  Post Load (0.3ms)  SELECT \"posts\".* FROM \"posts\" WHERE \"posts\".\"user_id\" IN (1, 2, 3, 4, 5, 6)\r\n\u5c71\u7530\u592a\u90ce \/ \u5148\u65e5\u306e\u65c5\u884c\u3067\u306e\u8a71\r\n\u9577\u702c\u6765 \/ \u6700\u8fd1\u5c11\u3057\u6c17\u306b\u306a\u3063\u305f\u3053\u3068\r\n\u7acb\u5ddd\u88d5\u7f8e \/ \u6628\u65e5\u306e\u51fa\u6765\u4e8b\r\n\u7acb\u5ddd\u88d5\u7f8e \/ \u5c71\u767b\u308a\u306b\u884c\u304d\u307e\u3057\u305f\r\n\u7acb\u5ddd\u88d5\u7f8e \/ Ruby on Rails\u306e\u65e5\r\n\u524d\u7530\u9054\u90ce \/ \u53cb\u4eba\u304c\u7d50\u5a5a\u3057\u307e\u3057\u305f\r\n\u524d\u7530\u9054\u90ce \/ \u30e9\u30f3\u30cb\u30f3\u30b0\u306e\u30b3\u30c4\r\n\u7d30\u5ddd\u4fee\u4e8c \/ \u697d\u3057\u3044\u4f11\u65e5\u306e\u904e\u3054\u3057\u65b9\r\n+----+----------+-------------------------+-------------------------+\r\n| id | name     | created_at              | updated_at              |\r\n+----+----------+-------------------------+-------------------------+\r\n| 1  | \u5c71\u7530\u592a\u90ce | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 2  | \u9577\u702c\u6765   | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 3  | \u7acb\u5ddd\u88d5\u7f8e | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 4  | \u524d\u7530\u9054\u90ce | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 5  | \u7d30\u5ddd\u4fee\u4e8c | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n| 6  | \u6728\u6751\u62d3\u78e8 | 2018-06-21 16:20:39 UTC | 2018-06-21 16:20:39 UTC |\r\n+----+----------+-------------------------+-------------------------+\r\n6 rows in set<\/pre>\n
\u3042\u3068\u3067\u8a66\u3057\u3066\u3082\u3089\u3044\u307e\u3059\u306e\u3067\u3001\u3053\u3053\u3067\u306f\u300cPost Load\u300d\u304c\u3059\u3054\u304f\u6e1b\u3063\u3066\u3044\u308b<\/strong><\/span>\u3068\u3044\u3046\u96f0\u56f2\u6c17\u3060\u3051\u3092\u3064\u304b\u3093\u3067\u304f\u3060\u3055\u3044\u3002<\/p>\n
includes\u306e\u52d5\u4f5c\u3092\u7406\u89e3\u3059\u308b\u305f\u3081\u306eWeb\u30a2\u30d7\u30ea\u3092\u4f5c\u6210\u3059\u308b<\/h2>\n
Rails\u306e\u52d5\u4f5c\u3092\u7406\u89e3\u3059\u308b\u305f\u3081\u306b\u3001scaffold<\/strong><\/span>\u3092\u4f7f\u3063\u3066Web\u30a2\u30d7\u30ea\u3092\u4f5c\u3063\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n
scaffold\u306e\u4f7f\u3044\u65b9\u306f\u3001\u4ee5\u4e0b\u306e\u8a18\u4e8b\u3067\u89e3\u8aac\u3057\u3066\u3044\u307e\u3059\u306e\u3067\u3001\u305c\u3072\u3054\u89a7\u304f\u3060\u3055\u3044\u3002<\/p>\n            \n                
\n                
\n                    
\n                    \n                    <\/div>\n                    
\n                    
\u3010Rails\u5165\u9580\u3011\u521d\u3081\u3066\u306eWeb\u30a2\u30d7\u30ea\u958b\u767a\u306a\u3089scaffold\u304c\u6700\u77ed\uff01<\/div>\n                    
\u66f4\u65b0\u65e5\uff1a2024\u5e745\u67086\u65e5<\/div>\n                    <\/div>\n                <\/div>\n                <\/div>\n            <\/a>\n            \n
\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001app\/samurai\/includes-demo<\/strong><\/span>\u30c7\u30a3\u30ec\u30af\u30c8\u30ea\u3092\u4f5c\u6210\u3057\u3001\u4ee5\u4e0b\u306e\u30b3\u30de\u30f3\u30c9\u3067Web\u30a2\u30d7\u30ea\u3092\u4f5c\u6210\u3057\u305f\u5834\u5408\u3092\u4f8b\u306b\u3001\u8aac\u660e\u3092\u7d9a\u3051\u307e\u3059\u3002<\/p>\n
bin\/rails generate scaffold User name:string\r\nbin\/rails generate scaffold Post user_id:integer title:string month:integer\r\nbin\/rails db:migrate\r\nbin\/rails server<\/pre>\n
\u30c7\u30fc\u30bf\u306e\u6e96\u5099<\/h3>\n
Rails\u30b3\u30f3\u30bd\u30fc\u30eb\u3092\u8d77\u52d5\u3057\u3066\u30c6\u30fc\u30d6\u30eb\u306b\u30c7\u30fc\u30bf\u3092\u5165\u529b\u3057\u307e\u3059\u3002<\/p>\n
scaffold\u3067\u4f5c\u6210\u3057\u3066\u3044\u307e\u3059\u306e\u3067\u3001http:\/\/localhost:3000\/users\/new<\/strong><\/span>\u3084\u3001http:\/\/localhost:3000\/posts\/new<\/strong><\/span>\u30671\u3064\u305a\u3064\u30c7\u30fc\u30bf\u3092\u5165\u529b\u3057\u3066\u3082\u69cb\u3044\u307e\u305b\u3093\u3002<\/p>\n
\uff081\uff09\u65b0\u3057\u3044\u300c\u7aef\u672b\u300d<\/strong><\/span>\u3092\u8d77\u52d5\u3057\u3066\u3001\u4ee5\u4e0b\u306e\u30b3\u30de\u30f3\u30c9\u30921\u884c\u305a\u3064\u9806\u756a\u306b\u5165\u529b\u3057\u307e\u3059\u3002<\/p>\n
cd app\/samurai\/includes-demo\r\nbin\/rails console<\/pre>\n
\uff082\uff09\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3092\u5165\u529b\u3057\u307e\u3059\u3002<\/p>\n
User.create(name:\"\u5c71\u7530\u592a\u90ce\")\r\nUser.create(name:\"\u9577\u702c\u6765\")\r\nUser.create(name:\"\u7acb\u5ddd\u88d5\u7f8e\")\r\nUser.create(name:\"\u524d\u7530\u9054\u90ce\")\r\nUser.create(name:\"\u7d30\u5ddd\u4fee\u4e8c\")\r\nUser.create(name:\"\u6728\u6751\u62d3\u78e8\")\r\nPost.create(user_id:5,title:\"\u697d\u3057\u3044\u4f11\u65e5\u306e\u904e\u3054\u3057\u65b9\" ,month:3)\r\nPost.create(user_id:1,title:\"\u5148\u65e5\u306e\u65c5\u884c\u3067\u306e\u8a71\" ,month:2)\r\nPost.create(user_id:3,title:\"\u6628\u65e5\u306e\u51fa\u6765\u4e8b\" ,month:12)\r\nPost.create(user_id:3,title:\"\u5c71\u767b\u308a\u306b\u884c\u304d\u307e\u3057\u305f\" ,month:8)\r\nPost.create(user_id:4,title:\"\u53cb\u4eba\u304c\u7d50\u5a5a\u3057\u307e\u3057\u305f\" ,month:4)\r\nPost.create(user_id:2,title:\"\u6700\u8fd1\u5c11\u3057\u6c17\u306b\u306a\u3063\u305f\u3053\u3068\" ,month:1)\r\nPost.create(user_id:4,title:\"\u30e9\u30f3\u30cb\u30f3\u30b0\u306e\u30b3\u30c4\" ,month:9)\r\nPost.create(user_id:3,title:\"Ruby on Rails\u306e\u65e5\" ,month:9)\r\nexit<\/pre>\n
User\u30c6\u30fc\u30d6\u30eb\u3068Post\u30c6\u30fc\u30d6\u30eb\u306b\u30c7\u30fc\u30bf\u304c\u5165\u529b\u3055\u308c\u3001Rails\u30b3\u30f3\u30bd\u30fc\u30eb\u304c\u7d42\u4e86\u3057\u307e\u3059\u3002<\/p>\n
\u30d6\u30e9\u30a6\u30b6\u3067\u30c7\u30fc\u30bf\u3092\u78ba\u8a8d\u3057\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n
\uff083\uff09\u30d6\u30e9\u30a6\u30b6\u3067\u300chttp:\/\/localhost:3000\/users\u300d<\/strong><\/span>\u306b\u30a2\u30af\u30bb\u30b9\u3057\u307e\u3059\u3002<\/p>\n
\"rails-include01\"<\/p>\n
\uff084\uff09\u30d6\u30e9\u30a6\u30b6\u3067\u300chttp:\/\/localhost:3000\/posts\u300d<\/strong><\/span>\u306b\u30a2\u30af\u30bb\u30b9\u3057\u307e\u3059\u3002<\/p>\n
\"rails-include02\"<\/p>\n
\u3046\u307e\u304f\u767b\u9332\u3055\u308c\u3066\u3044\u307e\u3059\u306d\uff01<\/p>\n
\u6b21\u306bUser\u30c6\u30fc\u30d6\u30eb\u3068Post\u30c6\u30fc\u30d6\u30eb\u3092\u95a2\u9023\u4ed8\u3051\u307e\u3059\u3002<\/p>\n
\uff085\uff09app\/models\/user.rb<\/strong><\/span>\u3092\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u7de8\u96c6\u3057\u307e\u3059\u3002<\/p>\n
\u5909\u66f4\u524d\uff1a<\/p>\n
class User < ApplicationRecord\r\nend<\/pre>\n
\u5909\u66f4\u5f8c\uff1a<\/p>\n
class User < ApplicationRecord\r\n  has_many :posts\r\nend<\/pre>\n
\uff086\uff09app\/models\/post.rb<\/strong><\/span>\u3092\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u7de8\u96c6\u3057\u307e\u3059\u3002<\/p>\n
\u5909\u66f4\u524d\uff1a<\/p>\n
class Post < ApplicationRecord\r\nend<\/pre>\n
\u5909\u66f4\u5f8c\uff1a<\/p>\n
class Post < ApplicationRecord\r\n  belongs_to :user\r\nend<\/pre>\n
\u3053\u308c\u3067\u3001\u6e96\u5099\u304c\u3067\u304d\u307e\u3057\u305f\u3002<\/p>\n
hirb gem\u3068hirb-unicode gem\u3092\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3059\u308b<\/h3>\n
\u3053\u306e\u5f8c\u3001includes\u306e\u52d5\u4f5c\u3092\u78ba\u8a8d\u3059\u308b\u969b\u3001Rails\u30b3\u30f3\u30bd\u30fc\u30eb\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n
Rails\u30b3\u30f3\u30bd\u30fc\u30eb\u3067\u51fa\u529b\u3057\u305f\u30c7\u30fc\u30bf\u306e\u898b\u6804\u3048\u3092\u826f\u304f\u306b\u3059\u308b\u305f\u3081\u306b\u3001\u4ee5\u4e0b\u306e2\u3064\u306egem\u3092\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n\n\t\n\n\t\n\t
gem<\/th>\u8aac\u660e<\/th>\n<\/tr>\n<\/thead>\n
hirb gem<\/td>\u51fa\u529b\u7d50\u679c\u3092\u8868\u5f62\u5f0f\u3067\u51fa\u529b\u3059\u308b<\/td>\n<\/tr>\n
hirb-unicode gem<\/td>\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u306e\u8868\u793a\u3092\u88dc\u6b63\u3059\u308b<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n
\uff081\uff09Gemfile<\/strong><\/span>\u306e\u6700\u7d42\u884c\u306b\u4ee5\u4e0b\u306e\u5185\u5bb9\u3092\u8ffd\u8a18\u3057\u307e\u3059\u3002<\/p>\n
gem 'hirb'\r\ngem 'hirb-unicode'<\/pre>\n
\uff082\uff09\u65b0\u3057\u3044\u300c\u7aef\u672b\u300d<\/strong><\/span>\u3092\u8d77\u52d5\u3057\u3066\u3001\u4ee5\u4e0b\u306e\u30b3\u30de\u30f3\u30c9\u30921\u884c\u305a\u3064\u9806\u756a\u306b\u5165\u529b\u3057\u307e\u3059\u3002<\/p>\n
cd app\/samurai\/includes-demo\r\nbundle install<\/pre>\n
\u3053\u308c\u3067\u3001hirb gem<\/strong><\/span>\u3068hirb-unicode gem<\/strong><\/span>\u304c\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3055\u308c\u307e\u3057\u305f\u3002<\/p>\n
\u95a2\u9023\u4ed8\u3051\u3089\u308c\u305f2\u3064\u306e\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u3092\u53c2\u7167\u3059\u308b\u65b9\u6cd5<\/h2>\n
\u95a2\u9023\u4ed8\u3051\u3089\u308c\u305f2\u3064\u306e\u30c6\u30fc\u30d6\u30eb\uff08\u4e0a\u3067\u7d39\u4ecb\u3057\u305fUser\u30c6\u30fc\u30d6\u30eb\u3068Post\u30c6\u30fc\u30d6\u30eb\uff09\u3067\u3001\u3059\u3079\u3066\u306epost\u306e\u6295\u7a3f\u8005\u3092\u53d6\u5f97\u3059\u308b\u65b9\u6cd5<\/strong><\/span>\u3092\u8003\u3048\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n
\u3053\u3053\u304b\u3089\u306f\u3001Rails\u30b3\u30f3\u30bd\u30fc\u30eb\u3067\u30b3\u30fc\u30c9\u3092\u5165\u529b\u3057\u3066\u3001\u5b9f\u884c\u7d50\u679c\u3092\u78ba\u8a8d\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n
\uff081\uff09\u4ee5\u4e0b\u306e\u30b3\u30de\u30f3\u30c9\u30921\u884c\u305a\u3064\u9806\u756a\u306b\u5165\u529b\u3057\u307e\u3059\u3002<\/p>\n
bin\/rails console\r\nHirb.enable<\/pre>\n
\uff082\uff09\u3059\u3079\u3066\u306epost\u306e\u30c7\u30fc\u30bf\u3092\u78ba\u8a8d\u3059\u308b\u305f\u3081\u306b\u3001\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3092\u5165\u529b\u3057\u307e\u3059\u3002<\/p>\n
Post.all<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n
  Post Load (2.1ms)  SELECT \"posts\".* FROM \"posts\"\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n| id | user_id | title            | month | created_at      | updated_at       |\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n| 1  | 5       | \u697d\u3057\u3044\u4f11\u65e5\u306e...  | 3     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 2  | 1       | \u5148\u65e5\u306e\u65c5\u884c\u3067\u306e\u8a71 | 2     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 3  | 3       | \u6628\u65e5\u306e\u51fa\u6765\u4e8b     | 12    | 2018-06-21 1... | 2018-06-21 14... |\r\n| 4  | 3       | \u5c71\u767b\u308a\u306b\u884c\u304d...  | 8     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 5  | 4       | \u53cb\u4eba\u304c\u7d50\u5a5a\u3057...  | 4     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 6  | 2       | \u6700\u8fd1\u5c11\u3057\u6c17\u306b...  | 1     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 7  | 4       | \u30e9\u30f3\u30cb\u30f3\u30b0\u306e\u30b3\u30c4 | 9     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 8  | 3       | Ruby on Rails... | 9     | 2018-06-21 1... | 2018-06-21 14... |\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n8 rows in set<\/pre>\n
\uff083\uff09\u3059\u3079\u3066\u306euser\u306e\u30c7\u30fc\u30bf\u3092\u78ba\u8a8d\u3059\u308b\u305f\u3081\u306b\u3001\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3092\u5165\u529b\u3057\u307e\u3059\u3002<\/p>\n
User.all<\/pre>\n
  User Load (0.2ms)  SELECT \"users\".* FROM \"users\"\r\n+----+----------+-------------------------+-------------------------+\r\n| id | name     | created_at              | updated_at              |\r\n+----+----------+-------------------------+-------------------------+\r\n| 1  | \u5c71\u7530\u592a\u90ce | 2018-06-21 14:17:20 UTC | 2018-06-21 14:17:20 UTC |\r\n| 2  | \u9577\u702c\u6765   | 2018-06-21 14:17:20 UTC | 2018-06-21 14:17:20 UTC |\r\n| 3  | \u7acb\u5ddd\u88d5\u7f8e | 2018-06-21 14:17:20 UTC | 2018-06-21 14:17:20 UTC |\r\n| 4  | \u524d\u7530\u9054\u90ce | 2018-06-21 14:17:20 UTC | 2018-06-21 14:17:20 UTC |\r\n| 5  | \u7d30\u5ddd\u4fee\u4e8c | 2018-06-21 14:17:20 UTC | 2018-06-21 14:17:20 UTC |\r\n| 6  | \u6728\u6751\u62d3\u78e8 | 2018-06-21 14:17:20 UTC | 2018-06-21 14:17:20 UTC |\r\n+----+----------+-------------------------+-------------------------+\r\n6 rows in set<\/pre>\n
\u624b\u9806\uff082\uff09\u3067\u8868\u793a\u3055\u308c\u305fuser_id\u3092\u4f7f\u3063\u3066\u3001\u624b\u9806\uff083\uff09\u3067\u8868\u793a\u3055\u308c\u305fUser\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u8a72\u5f53\u30e6\u30fc\u30b6\u30fc\u3092\u7279\u5b9a\u3057\u3066\u3001name\u3092\u53d6\u5f97\u3059\u308c\u3070ok\u3067\u3059\u306d\u3002<\/p>\n
\u3067\u306f\u3001\u305d\u308c\u3092\u5b9f\u73fe\u3059\u308b3\u3064\u306e\u65b9\u6cd5\u3092\u7d39\u4ecb\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n
Post.all<\/h3>\n
Post.all<\/strong><\/span>\u3067\u3059\u3079\u3066\u306epost\u3092\u53d6\u5f97\u3067\u304d\u307e\u3059\u306e\u3067\u3001\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3092\u5b9f\u884c\u3059\u308c\u3070\u3088\u3055\u305d\u3046\u3067\u3059\u3002<\/p>\n
Post.all.each { |post| puts \"\u2605 post.id=#{post.id} : post.user.name=#{post.user.name}\" }<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n
  Post Load (0.1ms)  SELECT \"posts\".* FROM \"posts\"\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 5], [\"LIMIT\", 1]]\r\n\u2605 post.id=1 : post.user.name=\u7d30\u5ddd\u4fee\u4e8c\r\n  User Load (0.0ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 1], [\"LIMIT\", 1]]\r\n\u2605 post.id=2 : post.user.name=\u5c71\u7530\u592a\u90ce\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 3], [\"LIMIT\", 1]]\r\n\u2605 post.id=3 : post.user.name=\u7acb\u5ddd\u88d5\u7f8e\r\n  User Load (0.0ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 3], [\"LIMIT\", 1]]\r\n\u2605 post.id=4 : post.user.name=\u7acb\u5ddd\u88d5\u7f8e\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 4], [\"LIMIT\", 1]]\r\n\u2605 post.id=5 : post.user.name=\u524d\u7530\u9054\u90ce\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 2], [\"LIMIT\", 1]]\r\n\u2605 post.id=6 : post.user.name=\u9577\u702c\u6765\r\n  User Load (0.3ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 4], [\"LIMIT\", 1]]\r\n\u2605 post.id=7 : post.user.name=\u524d\u7530\u9054\u90ce\r\n  User Load (0.2ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 3], [\"LIMIT\", 1]]\r\n\u2605 post.id=8 : post.user.name=\u7acb\u5ddd\u88d5\u7f8e\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n| id | user_id | title            | month | created_at      | updated_at       |\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n| 1  | 5       | \u697d\u3057\u3044\u4f11\u65e5\u306e...  | 3     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 2  | 1       | \u5148\u65e5\u306e\u65c5\u884c\u3067\u306e\u8a71 | 2     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 3  | 3       | \u6628\u65e5\u306e\u51fa\u6765\u4e8b     | 12    | 2018-06-21 1... | 2018-06-21 14... |\r\n| 4  | 3       | \u5c71\u767b\u308a\u306b\u884c\u304d...  | 8     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 5  | 4       | \u53cb\u4eba\u304c\u7d50\u5a5a\u3057...  | 4     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 6  | 2       | \u6700\u8fd1\u5c11\u3057\u6c17\u306b...  | 1     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 7  | 4       | \u30e9\u30f3\u30cb\u30f3\u30b0\u306e\u30b3\u30c4 | 9     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 8  | 3       | Ruby on Rails... | 9     | 2018-06-21 1... | 2018-06-21 14... |\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n8 rows in set<\/pre>\n
\u5b9f\u884c\u7d50\u679c\u3067\u2605\u304c\u8868\u793a\u3055\u308c\u3066\u3044\u308b\u884c\u3092\u3054\u89a7\u304f\u3060\u3055\u3044\u3002<\/p>\n
1\u756a\u306epost\u306e\u6295\u7a3f\u8005\u304c\u7d30\u5ddd\u4fee\u4e8c<\/strong><\/span>\u3067\u3042\u308b\u3053\u3068\u304c\u53d6\u5f97\u3067\u304d\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u305f\u3060\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306b\u306f\u5168\u90e8\u30679\u56de\u30a2\u30af\u30bb\u30b9\u3057\u3066\u3044\u307e\u3059\u306e\u3067\u3001N+1\u554f\u984c<\/strong><\/span>\u304c\u767a\u751f\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
joins<\/h3>\n
\u6b21\u306fjoins<\/strong><\/span>\u3092\u4f7f\u3046\u65b9\u6cd5\u3067\u3059\u3002<\/p>\n
\u8a66\u3057\u3066\u307f\u308b\u3068\u3001Post.all<\/strong><\/span>\u3068\u307b\u3068\u3093\u3069\u540c\u3058\u3067\u3059\u304c\u3001joins\u306f\u5185\u90e8\u7d50\u5408\uff08INNER JOIN\uff09<\/strong><\/span>\u3092\u884c\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n
Post.joins(:user).each { |post| puts \"\u2605 post.id=#{post.id} : post.user.name=#{post.user.name}\" }<\/pre>\n
\u5b9f\u884c\u7d50\u679c\uff1a<\/p>\n
  Post Load (0.2ms)  SELECT \"posts\".* FROM \"posts\" INNER JOIN \"users\" ON \"users\".\"id\" = \"posts\".\"user_id\"\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 5], [\"LIMIT\", 1]]\r\n\u2605 post.id=1 : post.user.name=\u7d30\u5ddd\u4fee\u4e8c\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 1], [\"LIMIT\", 1]]\r\n\u2605 post.id=2 : post.user.name=\u5c71\u7530\u592a\u90ce\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 3], [\"LIMIT\", 1]]\r\n\u2605 post.id=3 : post.user.name=\u7acb\u5ddd\u88d5\u7f8e\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 3], [\"LIMIT\", 1]]\r\n\u2605 post.id=4 : post.user.name=\u7acb\u5ddd\u88d5\u7f8e\r\n  User Load (0.2ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 4], [\"LIMIT\", 1]]\r\n\u2605 post.id=5 : post.user.name=\u524d\u7530\u9054\u90ce\r\n  User Load (0.2ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 2], [\"LIMIT\", 1]]\r\n\u2605 post.id=6 : post.user.name=\u9577\u702c\u6765\r\n  User Load (0.1ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 4], [\"LIMIT\", 1]]\r\n\u2605 post.id=7 : post.user.name=\u524d\u7530\u9054\u90ce\r\n  User Load (0.2ms)  SELECT  \"users\".* FROM \"users\" WHERE \"users\".\"id\" = ? LIMIT ?  [[\"id\", 3], [\"LIMIT\", 1]]\r\n\u2605 post.id=8 : post.user.name=\u7acb\u5ddd\u88d5\u7f8e\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n| id | user_id | title            | month | created_at      | updated_at       |\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n| 1  | 5       | \u697d\u3057\u3044\u4f11\u65e5\u306e...  | 3     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 2  | 1       | \u5148\u65e5\u306e\u65c5\u884c\u3067\u306e\u8a71 | 2     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 3  | 3       | \u6628\u65e5\u306e\u51fa\u6765\u4e8b     | 12    | 2018-06-21 1... | 2018-06-21 14... |\r\n| 4  | 3       | \u5c71\u767b\u308a\u306b\u884c\u304d...  | 8     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 5  | 4       | \u53cb\u4eba\u304c\u7d50\u5a5a\u3057...  | 4     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 6  | 2       | \u6700\u8fd1\u5c11\u3057\u6c17\u306b...  | 1     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 7  | 4       | \u30e9\u30f3\u30cb\u30f3\u30b0\u306e\u30b3\u30c4 | 9     | 2018-06-21 1... | 2018-06-21 14... |\r\n| 8  | 3       | Ruby on Rails... | 9     | 2018-06-21 1... | 2018-06-21 14... |\r\n+----+---------+------------------+-------+-----------------+------------------+\r\n8 rows in set<\/pre>\n
\u3053\u306e\u65b9\u6cd5\u3067\u3082\u3001\u3084\u306f\u308aN+1\u554f\u984c<\/strong><\/span>\u304c\u767a\u751f\u3057\u3066\u3044\u307e\u3059\u306d\u3002<\/p>\n
includes<\/h3>\n
3\u3064\u76ee\u306f\u3001includes<\/strong><\/span>\u3092\u4f7f\u3046\u65b9\u6cd5\u3067\u3059\u3002<\/p>\n
includes\u306f\u3001\u6761\u4ef6\u306b\u3088\u3063\u30662\u3064\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u307e\u3068\u3081\u308b\u65b9\u6cd5\u304c\u5909\u308f\u308b<\/strong><\/span>\u3068\u3044\u3046\u7279\u5fb4\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
\u8a73\u7d30\u306f\u7701\u304d\u307e\u3059\u304c\u3001\u4ee5\u4e0b\u306e2\u3064\u306e\u30d1\u30bf\u30fc\u30f3\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n