Rails:如何过滤结果? [英] Rails: How to filter results?

问题描述

在我的用户控制器的索引操作中，我能够在 ActiveRecord::Relation 对象 @users 中捕获与 current_user 属于同一城市的所有用户.在我看来，我能够遍历 @users 并显示结果.我想做的是为 current_user 提供更多选项来过滤结果.我想在视图中添加一个表单和过滤器按钮，这将允许current_user 选择过滤器，例如:

In the index action of my Users controller, I am able to capture all users belonging to the same city as the current_user in an ActiveRecord::Relation object @users. In my view I am able to iterate through @users and display the results. What I'd like to do is give the current_user further options to filter the results. I want to add a form and filter button in the view, which will allow the current_user to select filters, such as:

1. 最小年龄和最大年龄(下拉)
2. 宗教(复选框下拉菜单)
3. 饮食(复选框下拉)
4. 等等.

一旦 current_user 做出选择并点击过滤器，结果将根据选择的条件进行过滤.我想知道如何构建查询来执行此操作?

Once the current_user makes the selections and clicks on filter, the results will be filtered based on the criteria selected. I want to know how to build a query to do this?

推荐答案

通过在用户模型中创建作用域方法，在没有库的情况下自己完成此操作也相对简单.例如:

It's also relatively simple to do this yourself without a library by creating scope methods in your user model. For example:

 class User

   def self.filtered_by_age(opts = {})
     min = opts[:min]
     max = opts[:max]
     user = User.arel_table

     if min && max
       self.where(:age => min..max)
     elsif min && !max
       self.where(user[:age].gt(min))
     elsif max && !min
       self.where(user[:age].lt(max))
     else
       self.all
     end
   end

 end

然后你可以打电话

@users.filtered_by_age(min: 25, max: 52)

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