小编the*_*s11的帖子

我试图从postgres数据库中提取行,我可以将它们拉出来但是当我尝试随机时,我会在随机附近得到一个语法错误.

错误

PG::Error: ERROR:  syntax error at or near "rand"
LINE 1: ...  "hashtags".* FROM "hashtags"  ORDER BY tweet_id rand LIMIT...
                                                             ^
: SELECT  "hashtags".* FROM "hashtags"  ORDER BY tweet_id rand LIMIT 4

把它拉出来的代码

<div id="hashtags">
<% Hashtag.order("tweet_id desc").limit(4).each do |hashtag| %>
   <blockquote><%= hashtag.content %></blockquote>
   <div class="from">&mdash; @<%= hashtag.screen_name %></div>
 <% end %>
</div>

所以我在删除使用New-Item创建的SymbolicLinks时遇到问题

New-Item -ItemType SymbolicLink -Path C:\SPI -Target "C:\Users\Chino\Dropbox (Reserve Membership)\"

我需要删除它,因为它有错误的-Target应该是

New-Item -ItemType SymbolicLink -Path C:\SPI -Target "C:\Users\Chino\Dropbox (Reserve Membership)\SPI"

如果A.我可以轻松删除该路径并重新分配目标或更新目标.

有一些问题得到Nokogiri及其文档的正确设置有点粗略开始.

我正在尝试解析XML文件:http://www.kongregate.com/games_for_your_site.xml

它返回游戏内的多个游戏,每个游戏都有一个标题,desc等....

<gameset>
  <game>
    <id>160342</id>
    <title>Tricky Rick</title>
    <thumbnail>
      http://cdn3.kongregate.com/game_icons/0042/7180/KONG_icon250x200_site.png?21656-op
    </thumbnail>
    <launch_date>2012-12-12</launch_date>
    <category>Puzzle</category>
    <flash_file>
      http://external.kongregate-games.com/gamez/0016/0342/live/embeddable_160342.swf
    </flash_file>
    <width>640</width>
    <height>480</height>
    <url>
      http://www.kongregate.com/games/tAMAS_Games/tricky-rick
    </url>
    <description>
      Help Rick to collect all the stolen fuel to refuel his spaceship and fly away from the planet. Use hammer, bombs, jetpack and other useful stuff to solve puzzles!
    </description>
    <instructions>
      WASD \ Arrow Keys &#8211; move; S \ Down Arrow &#8211; take\release an object; CNTRL &#8211; interaction with objects: throw, hammer strike, invisibility mode; …

我试图after_find在我的模型中使用回调，我在尝试让它实际更新它在after_find方法中找到的行时遇到了问题。它抛出一个无方法错误

错误

Completed 500 Internal Server Error in 299ms

ActionView::Template::Error (undefined method `+' for nil:NilClass):
    1: <div id="hashtags" class="twitter-hashtag-voting-block-v1">
    2: <% @random_hashtag_pull.each do |hashtag| %>
    3: <div class="span4 twitter-spans-v1" id="<%= hashtag.id %>">
    4:      <div id="tweet-block-v1" class="hashtag-tweet-database-container">
    5:      <div class="tweet-block-border-v1">
  app/models/hashtag.rb:46:in `update_view_count'
  app/views/shared/_vote_tweets.html.erb:2:in `_app_views_shared__vote_tweets_html_erb__2738953379660121418_70243350609340'
  app/views/hashtags/create.js.erb:2:in `_app_views_hashtags_create_js_erb___1440072038737667206_70243345272440'
  app/controllers/hashtags_controller.rb:23:in `create'

标签控制器

class HashtagsController < ApplicationController
  def home 
  end
  def vote
    @random_hashtags = Hashtag.order("RANDOM()").limit(4)
  end
  def show
  end
  def index
  end
  def create 
    Hashtag.pull_hashtag(params[:hashtag])
    @random_hashtag_pull = Hashtag.random_hashtags_pull
    respond_to do |format| …