ruby-on-rails - Rails 帮助 ActionView::Template::Error 提示:没有运算符匹配给定的名称和参数类型。您可能需要添加显式类型转换

Question

我的 Rails 应用程序在我的 locale 机器上使用 mysql 运行良好。但是在 Heroku 上我得到以下错误:http://pastie.org/1697772

我的分类助手:

module KategorisHelper
def sortkat(column, title = nil)
  title ||= column.titleize
  css_class = column == sort_column ? "current #{sort_direction}" : nil
  direction = column == sort_column && sort_direction == "asc" ? "desc" : "asc"
  link_to title, {:sort => column, :direction => direction}, {:class => css_class}
end
end

我的 Kategoris Controller :

class KategorisController < ApplicationController
    @kategori = Kategori.find(:first, :conditions => "cached_slug = '#{params[:id]}'")
    @konkurrencer = @kategori.konkurrancers.order(sort_column + " " + sort_direction)
    @titel = @kategori.name
  end

private

def sort_column
  Konkurrancer.column_names.include?(params[:sort]) ? params[:sort] : "created_at"
end

  def sort_direction
    %w[desc asc].include?(params[:direction]) ? params[:direction] : "desc"
  end
end

我的模型:

class Kategori < ActiveRecord::Base
    has_many :konkurrancers
    has_friendly_id :name, :use_slug => true
end

class Konkurrancer < ActiveRecord::Base
    belongs_to :kategori
    has_friendly_id :name, :use_slug => true
end

Answer 1

PostgreSQL 无法原谅我的 kategori_id 是 varchar。

将其更改为整数。问题解决了。