这是我的两个模特
class Comment < ActiveRecord::Base
belongs_to :phone
end
class Phone < ActiveRecord::Base
has_many :comments, :dependent => :destroy
end
这是表的架构
ActiveRecord::Schema.define(version: 20131119231249) do
create_table "comments", force: true do |t|
t.string "username"
t.string "ipaddy"
t.text "pcomments"
t.string "company"
t.string "calltype"
t.datetime "created_at"
t.datetime "updated_at"
t.integer "pnumber"
t.string "source"
end
create_table "phones", force: true do |t|
t.integer "pnumber"
t.text "mrcomment"
t.integer "ccount"
t.datetime "created_at"
t.datetime "updated_at"
end
end
以下是适用的原始SQL
SELECT phones.ccount ,
comments.*
FROM phones
INNER JOIN comments
ON phones.pnumber = comments.pnumber;
当我在控制器中运行以下内容时
@phones = Phone.select("phones.ccount, comments.*").joins(:comments).where(:comments => {comments.pnumber => phones.pnumber})
我收到以下错误
undefined local variable or method `comments' for #<FrontPageController:0x00000003c56c70>
非常感谢任何有关活动记录声明的帮助
答案 0 :(得分:0)
好像你错误地使用了select()。您是否阅读过文档:http://apidock.com/rails/ActiveRecord/QueryMethods/select?
来自docs的:“第二:修改查询的SELECT语句,以便只检索某些字段:”
查询的语法应该更像(使用标准示例):
l = Location.where(["id = ?", id]).select("name, website, city").first.