我正在部署英雄并且它很成功但是当我去英雄网址时我得到了500错误。这是我的日志文件
2016-11-28T22:19:09.106733+00:00 app[web.1]: 10: <tbody>
2016-11-28T22:19:09.106735+00:00 app[web.1]: 11: <% @users.try(:each) do |user| %>
2016-11-28T22:19:09.106736+00:00 app[web.1]: 13: <td><%= user.first_name + " " + user.last_name %></td>
2016-11-28T22:19:09.106735+00:00 app[web.1]: 12: <tr>
2016-11-28T22:19:09.106737+00:00 app[web.1]: 14: <td><%= user.email %></td>
2016-11-28T22:19:09.106737+00:00 app[web.1]: 15: <td>
2016-11-28T22:19:09.106738+00:00 app[web.1]: 16: <% if follow = user.follows.find_by(follows: user.id) %>
2016-11-28T22:19:09.106742+00:00 app[web.1]: app/views/follows/index.html.erb:11:in `_app_views_follows_index_html_erb___1812592661839220487_70215972087760'
2016-11-28T22:19:09.106741+00:00 app[web.1]: app/views/follows/index.html.erb:13:in `block in _app_views_follows_index_html_erb___1812592661839220487_70215972087760'
2016-11-28T22:19:09.106742+00:00 app[web.1]:
2016-11-28T22:19:09.106743+00:00 app[web.1]:
2016-11-28T22:24:13.636808+00:00 heroku[router]: at=info method=GET path="/follows" host=sn-sql.herokuapp.com request_id=fb1f9eee-890b-4227-8185-2ada91825cb6 fwd="141.225.80.1" dyno=web.1 connect=0ms service=30ms status=500 bytes=1759
2016-11-28T22:24:13.634688+00:00 app[web.1]: Started GET "/follows" for 141.225.80.1 at 2016-11-28 22:24:13 +0000
2016-11-28T22:24:13.637819+00:00 app[web.1]: Processing by FollowsController#index as HTML
2016-11-28T22:24:13.642862+00:00 app[web.1]: [1m[36mUser Load (0.9ms)[0m [1mSELECT "users".* FROM "users"[0m
2016-11-28T22:24:13.645429+00:00 app[web.1]: Rendered follows/index.html.erb within layouts/application (4.4ms)
2016-11-28T22:24:13.645666+00:00 app[web.1]: Completed 500 Internal Server Error in 8ms (ActiveRecord: 0.9ms)
2016-11-28T22:24:13.647633+00:00 app[web.1]:
2016-11-28T22:24:13.647634+00:00 app[web.1]: ActionView::Template::Error (undefined method `+' for nil:NilClass):
2016-11-28T22:24:13.647635+00:00 app[web.1]: 10: <tbody>
2016-11-28T22:24:13.647636+00:00 app[web.1]: 11: <% @users.try(:each) do |user| %>
2016-11-28T22:24:13.647637+00:00 app[web.1]: 12: <tr>
2016-11-28T22:24:13.647637+00:00 app[web.1]: 13: <td><%= user.first_name + " " + user.last_name %></td>
2016-11-28T22:24:13.647638+00:00 app[web.1]: 14: <td><%= user.email %></td>
2016-11-28T22:24:13.647639+00:00 app[web.1]: 15: <td>
2016-11-28T22:24:13.647639+00:00 app[web.1]: 16: <% if follow = user.follows.find_by(follows: user.id) %>
2016-11-28T22:24:13.647640+00:00 app[web.1]: app/views/follows/index.html.erb:13:in `block in _app_views_follows_index_html_erb___1812592661839220487_70215972087760'
2016-11-28T22:24:13.647641+00:00 app[web.1]: app/views/follows/index.html.erb:11:in `_app_views_follows_index_html_erb___1812592661839220487_70215972087760'
2016-11-28T22:24:13.647642+00:00 app[web.1]:
2016-11-28T22:24:13.647642+00:00 app[web.1]:
2016-11-28T22:28:05.898802+00:00 app[web.1]: Started HEAD "/" for 54.80.172.253 at 2016-11-28 22:28:05 +0000
2016-11-28T22:28:05.900540+00:00 app[web.1]: Processing by NewsFeedController#index as HTML
2016-11-28T22:28:05.903485+00:00 app[web.1]: Rendered posts/_form.html.erb (1.4ms)
2016-11-28T22:28:05.904672+00:00 app[web.1]: [1m[35mPost Load (0.8ms)[0m SELECT "posts".* FROM "posts"
2016-11-28T22:28:05.907075+00:00 app[web.1]: [1m[36mUser Load (1.0ms)[0m [1mSELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT 1[0m [["id", 1]]
2016-11-28T22:28:05.913989+00:00 app[web.1]: Rendered posts/_post.html.erb (9.0ms)
2016-11-28T22:28:05.914213+00:00 app[web.1]: Rendered news_feed/index.html.erb within layouts/application (12.3ms)
2016-11-28T22:28:05.914387+00:00 app[web.1]: Completed 500 Internal Server Error in 14ms (ActiveRecord: 1.8ms)
2016-11-28T22:28:05.915476+00:00 app[web.1]:
2016-11-28T22:28:05.915478+00:00 app[web.1]: ActionView::Template::Error (undefined method `id' for nil:NilClass):
2016-11-28T22:28:05.915479+00:00 app[web.1]: 20: </div>
2016-11-28T22:28:05.915480+00:00 app[web.1]: 21: <div class="panel-body">
2016-11-28T22:28:05.915481+00:00 app[web.1]: 22: <p><%= post.post_text %></p>
2016-11-28T22:28:05.915484+00:00 app[web.1]: 23: <% if like = post.likes.find_by(user_id: current_user.id) %>
2016-11-28T22:28:05.915485+00:00 app[web.1]: 24: <%= link_to '<i class="fa fa-thumbs-down" aria-hidden="true"></i> Unlike'.html_safe, like, method: 'delete',class: "" %>
2016-11-28T22:28:05.915486+00:00 app[web.1]: 25: <% else %>
2016-11-28T22:28:05.915487+00:00 app[web.1]: 26: <%= link_to '<i class="fa fa-thumbs-up" aria-hidden="true"></i> Like'.html_safe, likes_path({post_id: post.id}), method: 'post',class: "" %>
2016-11-28T22:28:05.915488+00:00 app[web.1]: app/views/posts/_post.html.erb:23:in `_app_views_posts__post_html_erb__2305306643930163929_70215970144600'
2016-11-28T22:28:05.915489+00:00 app[web.1]: app/views/news_feed/index.html.erb:3:in `block in _app_views_news_feed_index_html_erb__1204754539652968054_70215970424660'
2016-11-28T22:28:05.915490+00:00 app[web.1]: app/views/news_feed/index.html.erb:2:in `_app_views_news_feed_index_html_erb__1204754539652968054_70215970424660'
2016-11-28T22:28:05.915491+00:00 app[web.1]:
2016-11-28T22:28:05.915491+00:00 app[web.1]:
2016-11-28T22:28:05.907994+00:00 heroku[router]: at=info method=HEAD path="/" host=sn-sql.herokuapp.com request_id=85b21e2a-cdc7-4bfe-a3b5-8ff1ca1a460e fwd="54.80.172.253" dyno=web.1 connect=0ms service=19ms status=500 bytes=277
不知道发生了什么，因为它在我的本地服务器上完全正常工作。不确定日志中的任何含义。任何帮助都会很棒。
答案 0 :(得分：0)
首先，您应该尝试习惯阅读日志，因为如果您开始开发rails应用程序，它是您需要擅长调试的主要内容之一。
他们的日志告诉你这里有什么错误
ActionView::Template::Error (undefined method `+' for nil:NilClass):
基本上是说你试图将nil添加到某些内容中，这显然没有意义，因此错误。如果你看下面的块，你可以看到你试图在这里添加用户的名字和姓氏
<td><%= user.first_name + " " + user.last_name %></td>
因此该用户缺少名字或姓氏。所以你需要的只是一个条件，以确保在你添加它们之前存在它们，比如
<% if user.first_name && user.last_name %>
<td><%= user.first_name + " " + user.last_name %></td>
whatever else...
<% end %>
你还有另一个错误
ActionView::Template::Error (undefined method `id' for nil:NilClass):