思考 – 狮身人面像指数最低
我有产品和价格模型，其中：
class Product < AR::Base has_many :prices # there are several types of prices, eg for guests, users et.c. 我想按价格值对产品进行索引和分类，属于该产品和确切的price_type。
ThinkingSphinx::Index.define :product, with: :active_record do indexes name indexes k1c indexes catalogue_code indexes created_at, sortable: true indexes prices(:value), as: :price, sortable: true # TODO has :category_id has :brand_id has :kind_cd has :price_id end
在rake ts:rebuild I get that
rake aborted! NoMethodError: undefined method `type' for nil:NilClass /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/attribute/type.rb:64:in `type_from_database' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/attribute/type.rb:17:in `type' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/attribute.rb:4:in `type' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/attribute/sphinx_presenter.rb:30:in `sphinx_type' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/attribute/sphinx_presenter.rb:18:in `collection_type' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/sql_source.rb:96:in `block in append_presenter_to_attribute_array' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/sql_source.rb:93:in `each' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/sql_source.rb:93:in `append_presenter_to_attribute_array' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/sql_source.rb:132:in `prepare_for_render' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/active_record/sql_source.rb:65:in `render' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/riddle-1.5.10/lib/riddle/configuration/index.rb:29:in `block in render' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/riddle-1.5.10/lib/riddle/configuration/index.rb:29:in `collect' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/riddle-1.5.10/lib/riddle/configuration/index.rb:29:in `render' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/core/index.rb:53:in `render' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/riddle-1.5.10/lib/riddle/configuration.rb:41:in `block in render' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/riddle-1.5.10/lib/riddle/configuration.rb:41:in `collect' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/riddle-1.5.10/lib/riddle/configuration.rb:41:in `render' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/configuration.rb:88:in `render' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/configuration.rb:94:in `block in render_to_file' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/configuration.rb:94:in `render_to_file' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/rake_interface.rb:13:in `configure' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/rake_interface.rb:24:in `index' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/gems/thinking-sphinx-3.1.0/lib/thinking_sphinx/tasks.rb:9:in `block (2 levels) in ' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/bin/ruby_executable_hooks:15:in `eval' /home/asiniy/.rvm/gems/ruby-2.1.0@zhivojoffice/bin/ruby_executable_hooks:15:in `' Tasks: TOP => ts:rebuild => ts:index
需要我写一个原始的SQL查询还是有另一种方法？
UPD
模拟sql查询得到一个价格（之后我想按价格订购）：
SELECT "prices".* FROM "prices" WHERE "prices"."product_id" = $1 AND "prices"."price_type_id" = 1 LIMIT 1
我的价格模型。 price_types的数量大约是5，很少变化。
class Price < ActiveRecord::Base validates :price_type, :value, :product, presence: true validates :price_type, uniqueness: { scope: :product } validates :value, numericality: { greater_than: 0.0 } belongs_to :price_type belongs_to :product end
这里有几点需要注意。
首先：属性更适合排序（它们的性质可以排序）……但是，如果你想按最低价格排序，那么你将需要一个SQL片段：
has 'MIN(prices.value)', as: :price, type: :float
您还需要确保在单独的字段或属性中引用prices关联，或者在join调用中显式引用prices关联，以确保表实际上是生成的SQL查询中的连接的一部分：
join prices
但是，您看到的错误与此无关 – 它抱怨它无法确定属性的类型，因为指定的列不存在。 我很确定这是来自你的price_id属性，它可能应该通过prices关联：
has prices.id, as: :price_ids
进行此更改还有确保prices表存在SQL连接的额外好处，因此您不需要索引定义中的join prices行。