{"author_name":"nkgt_chkonk","categories":["Rails","Ruby"],"provider_url":"https://hatena.blog","url":"https://nekogata.hatenablog.com/entry/2014/10/19/031426","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fnekogata.hatenablog.com%2Fentry%2F2014%2F10%2F19%2F031426\" title=\"ActiveRecord \u306e dup \u306e\u6319\u52d5 - \u732b\u578b\u306e\u84c4\u97f3\u6a5f\u306f 1 \u5206\u9593\u306b 45 \u56de\u306b\u3083\u3042\u3068\u9cf4\u304f\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","published":"2014-10-19 03:14:26","version":"1.0","title":"ActiveRecord \u306e dup \u306e\u6319\u52d5","type":"rich","blog_title":"\u732b\u578b\u306e\u84c4\u97f3\u6a5f\u306f 1 \u5206\u9593\u306b 45 \u56de\u306b\u3083\u3042\u3068\u9cf4\u304f","height":"190","blog_url":"https://nekogata.hatenablog.com/","description":"\u3072\u3068\u3053\u3068\u3067\u8a00\u3046\u3068\u3001 ActiveRecord \u306b\u306f dirtry \u306a attribute \u3092\u8ffd\u8de1\u3059\u308b\u305f\u3081\u306e\u4fbf\u5229\u306a\u30e1\u30bd\u30c3\u30c9\u7fa4\u304c\u5b9a\u7fa9\u3055\u308c\u3066\u3044\u307e\u3059\u304c\u3001dup \u3068\u3068\u3082\u306b\u3053\u308c\u3089\u3092\u6271\u3046\u3068\u304d\u306b\u306f\u8981\u6ce8\u610f\u3067\u3059\u3088\u3001\u3068\u3044\u3046\u304a\u8a71\u3067\u3059\u3002 _was \u3068\u304b _changed? \u306f\u4fbf\u5229 dirty \u306a attribute \u3092\u8ffd\u8de1\u3059\u308b\u3063\u3066\u306e\u306f\u3069\u3046\u3044\u3046\u3053\u3068\u304b\u3063\u3066\u3044\u3046\u3068\u3001\u305f\u3068\u3048\u3070\u3053\u3046\u3044\u3046\u3053\u3068\u3067\u3059\u3002 # DB\u304b\u3089user\u3092\u3072\u3068\u308a\u5f15\u3044\u3066\u304f\u308b user = User.first user.name # => \"shinpei\" user.name_was # => \"shinpei\" user.name_changed? # => fa\u2026","width":"100%","provider_name":"Hatena Blog","image_url":null,"author_url":"https://blog.hatena.ne.jp/nkgt_chkonk/"}