Rails 3.1.Heroku PGError:运算符不存在:字符变化=整数

Question

修复错误有点麻烦.

一切都适用于本地机器.在PG上,heroku是错误的.

这是日志:

  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m ActionView::Template::Error (PGEr
  ror: ERROR:  operator does not exist: character varying = integer
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m LINE 1: ...T "reviews".* FROM "re
  views"  WHERE "reviews"."trip_id" = 32
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m : SELECT "reviews".* FROM "review
  s"  WHERE "reviews"."trip_id" = 32):
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m     31:   <div style='display:non
  e'>
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m     33:      <% for review in @tr
  ip.reviews %>
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m     34:
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m     32:    <div id="inline">
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m HINT:  No operator matches the gi
  ven name and argument type(s). You might need to add explicit type casts.
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m   app/controllers/trips_controlle
  r.rb:21:in `show'
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m cache: [GET /trips/32] miss
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m     36:     <li> <%= review.conte
  nt %> </li>
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m     35:     <ul>
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m   app/views/trips/show.html.erb:3
  3:in `_app_views_trips_show_html_erb__3301405670044045300_69859019468960'
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m Completed 500 Internal Server Err
  or in 86ms
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m   Parameters: {"id"=>"32"}
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m   Processing by TripsController#s
  how as HTML
  ?[32m2012-01-09T19:52:24+00:00 app[web.1]:?[0m Rendered trips/show.html.erb with
  in layouts/application (81.8ms)

不确定在哪里,错误发生以及如何解决它.

reviews.rb

 class Review < ActiveRecord::Base
  belongs_to :trip
 end

 class Trip < ActiveRecord::Base
  has_many :reviews, :dependent => :destroy
  attr_accessible, :reviews_attributes

  accepts_nested_attributes_for :reviews, :reject_if => lambda { |a| a[:name].blank? }, :allow_destroy => true
 end 

show.html.rb

 <%= link_to "Read Reviews", '#inline',  :id => 'various1', :class => 'review' %>  

 <div style='display:none'>  
   <div id="inline">
      <% for review in @trip.reviews %>  
       <ul>
         <li> <%= review.content %> </li>
         <li> <i> <%= review.name %> </i> </li>
       </ul>
     <% end %>  
  </div> 
 </div>

令我困惑的是,我有两个几乎相同的模型,但它们运作良好.

谢谢!

Answer 1

你的问题在这里:

WHERE "reviews"."trip_id" = 32

并且错误消息说:

运算符不存在:字符变化=整数

所以你已经用字符串而不是整数创建了trip_id列reviews.这在SQLite中可以正常工作,因为SQLite的类型系统相当松散,但它在PostgreSQL中不起作用,因为PostgreSQL相当严格.

您可以尝试添加迁移来修复以下类型trip_id:

def change
  change_column :reviews, :trip_id, :integer
end

如果这不起作用,则删除并重新创建表:

def change
  drop_table :reviews
  create_table :reviews do |t|
    #...
    t.integer :trip_id
    #...
  end
end

如果您有要保留的数据并且change_column不起作用,您还可以通过原始SQL执行ALTER TABLE :

def change
  execute %q{
    alter table reviews
    alter column trip_id
    type int using cast(trip_id as int)
  }
end

这应该适用于PostgreSQL(但不适用于SQLite),只要您的数据中没有任何损坏的数据trip_id.

一旦你完成了整理,你应该安装PostgreSQL并将你的开发环境切换到那个.在SQLite之上开发并部署到PostgreSQL(或者在一个数据库上开发并在任何其他数据库之上进行部署)是一个坏主意,会给你带来各种各样的悲伤和困惑.