Question

我希望显示所有发现日的所有价格。

控制器视图中的

def view
 @travel = Travel.find(params[:id])
 @car = Car.find(:first, :conditions => ["id = ?", @travel.car_id])
 @start_day = StartDay.find(:all, :conditions => ["travel_id = ?", @travel.id])
 @import_price = ImportPrice.find(:all, 
        :conditions => ["begin_date = ? and car_code = ?",
                        @start_day.day, @car.short_name])
end

当我添加值@import_price时出现错误：

undefined method `day' for #<Array:0x7feb70d56fe8>

我如何正确选择所有日子？

提前致谢。

ruby 1.8.7 rails 2.3

Answer 1

是的，因为你的@start_day对象正在返回一个数组。如果你想获取日期字段数据，你可以这样做：

def view
 @travel = Travel.find(params[:id])
 @car = Car.find(:first, :conditions => ["id = ?", @travel.car_id])
 @start_day = StartDay.find(:all, :conditions => ["travel_id = ?", @travel.id])
 @import_price = ImportPrice.find(:all, 
        :conditions => ["begin_date in ? and car_code = ?",
                        @start_day.map{|x| x.day}, @car.short_name])
end

或

def view
 @travel = Travel.find(params[:id])
 @car = Car.find(:first, :conditions => ["id = ?", @travel.car_id])
 @start_day = StartDay.find(:first, :conditions => ["travel_id = ?", @travel.id])
 @import_price = ImportPrice.find(:all, 
        :conditions => ["begin_date = ? and car_code = ?",
                        @start_day.day}, @car.short_name])
end

Answer 2

这对你有用吗？

@start_day = StartDay.find(:first, :conditions => ["travel_id = ?", @travel.id], :order => "id DESC")
 @import_price = ImportPrice.find(:all, 
        :conditions => ["begin_date = ? and car_code = ?",
                        @start_day.day, @car.short_name])

Answer 3

我的回答是;我也有机会根据您的模型关联（如果它们在那里）重写一点：

def view
  @travel = Travel.find(params[:id])
  @car = Car.first.where(:id => @travel.car_id) #@travel.car? I don't know if that will work but it looks like it would
  @start_day = StartDay.where(:travel_id => @travel.id) # wouldn't @travel.start_days work?
  @import_price = ImportPrice.where("begin_date IN (?) and car_code = ?", 
    @start_day.map(&:day), @car.short_name)
end

使用@start_day.map(&:day)获取您要查询的所有日期。

Answer 4

错误原因：

StartDay.find(:all, :conditions => ["travel_id = ?", @travel.id])

您收到此错误是因为代码返回了一个符合您条件的所有对象（即数据库表中的所有行）的数组。即使数据库表中只有一个条目符合您的条件，返回也将采用数组格式。

解决方案：

一种解决方案可以是：

 @start_day = StartDay.find(:first, :conditions => ["travel_id = ?", @travel.id])

另一种解决方案可以是：

@import_price = ImportPrice.find(:all, 
        :conditions => ["begin_date in ? and car_code = ?",
                        @start_day.map{|x| x.day}, @car.short_name])

#lite的未定义方法：0x7feb70d56fe8> </array：0x7feb70d56fe8>

4 个答案: