Rails AjaxDatatablesRails::ActiveRecord LEFT JOIN 到同一模型导致搜索错误

Question

交易模型有两个引用仓库模型对象的字段。这导致搜索过程中出现错误。按任何这些字段进行搜索或排序仅使用第一个 left_join 中的数据。

class Transaction < ApplicationRecord belongs_to :stored_product belongs_to :user belongs_to :from_stockroom, class_name: 'Stockroom', foreign_key: 'from_stockroom_id', optional: true belongs_to :to_stockroom, class_name: 'Stockroom', foreign_key: 'to_stockroom_id', optional: true attr_accessor :user_selection

Answer 1

我尝试了很多方法来修复这个错误。最终我能够做到。我将在这里留下帖子以防其他人遇到同样的错误。或者如果有人知道更好的方法来解决它。自定义 AjaxDatatablesRails filter_records(records) 方法并在 get_raw_records 中使用 AS 来处理我的请求对我有用。

class TransactionsDatatable < AjaxDatatablesRails::ActiveRecord
  extend Forwardable
  include Rails.application.routes.url_helpers
  def_delegators :@view, :current_user

  def initialize(params, opts = {})
    @view = opts[:view_context]
    super
  end

  def view_columns
    @view_columns ||= {
      id: { source: 'Transaction.id', cond: :eq, searchable: true },
      stored_product_id: { source: 'StoredProduct.name', searchable: true },
      user_id: { source: 'User.name', cond: :like, searchable: true },
      from_stockroom_id: { source: 'from_stockroom_name', cond: :like, searchable: true, orderable: true },
      to_stockroom_id: { source: 'to_stockroom_name', cond: :like, searchable: true, orderable: true },
      quantity: { source: 'Transaction.quantity', searchable: false, orderable: false },
      comment: { source: 'Transaction.comment', cond: :like, searchable: true, orderable: false },
      created_at: { source: 'Transaction.created_at', searchable: false }
    }
  end

  def data
    records.map do |record|
      {
        id: record.id,
        stored_product_id: record.stored_product.name,
        user_id: record.user.name,
        from_stockroom_id: record.from_stockroom.present? ? record.from_stockroom.name : 'Поставка',
        to_stockroom_id: record.to_stockroom.present? ? record.to_stockroom.name : 'Списание',
        quantity: record.quantity,
        comment: record.comment,
        created_at: record.created_at.strftime('%d.%m.%Y'),
        DT_RowId: record.id
      }
    end
  end

  def get_raw_records
    Transaction.where(deleted: false)
               .joins(:stored_product, :user)
               .joins('LEFT JOIN stockrooms AS from_stockrooms ON from_stockrooms.id = transactions.from_stockroom_id')
               .joins('LEFT JOIN stockrooms AS to_stockrooms ON to_stockrooms.id = transactions.to_stockroom_id')
               .select('transactions.*, from_stockrooms.name as from_stockroom_name, to_stockrooms.name as to_stockroom_name')
  end

  def filter_records(records)
    to_search_value = params[:columns]["4"]["search"]["value"]
    from_search_value = params[:columns]["3"]["search"]["value"]

    records = records.where("LOWER(from_stockrooms.name) LIKE ?", "%#{to_search_value.downcase}%") if to_search_value.present? 
    records = records.where("LOWER(to_stockrooms.name) LIKE ?", "%#{from_search_value.downcase}%") if from_search_value.present? 
    records = records.where(build_conditions)

    return records unless search_value.present?

    records.or(records.where("LOWER(to_stockrooms.name) LIKE ?", "%#{params["search"]["value"].downcase}%"))
           .or(records.where("LOWER(from_stockrooms.name) LIKE ?", "%#{params["search"]["value"].downcase}%"))
  end
end