Question

所以我有一个类似于枚举值的模型：

class Connection < ActiveRecord::Base
  enum request_status: { pending: 0, accepted: 1, rejected: 2, removed: 3 }
end

但是，我有一个params值，我想设置并执行查询 - 这样的事情：

@connections = current_user.all_connections.where(request_status: params[:request_status])

current_user.all_connections返回一个AR对象（也就是......它也是一个带有where调用的查询方法）。

我面临的问题是，现在，上面的查询返回一个空集合。我相信的原因是API docs in Rails：

enum属性的条件必须使用a的序数值枚举。

鉴于params[:request_status]将如下所示：

Parameters: {"request_status"=>"accepted"}

如何修改where查询以反映这一点？我知道另一个选择只是将参数修改为序数值，而不是字符串，但我很好奇我如何用字符串值而不是序数值来实现这个？

修改1

以下是服务器日志：

Started GET "/connections?request_status=accepted" for 127.0.0.1 at 2016-01-04 20:23:08 -0500
Processing by ConnectionsController#index as HTML
  Parameters: {"request_status"=>"accepted"}
  User Load (2.7ms)  SELECT  "users".* FROM "users"  WHERE "users"."id" = 3  ORDER BY "users"."id" ASC LIMIT 1
  FamilyTree Load (1.7ms)  SELECT  "family_trees".* FROM "family_trees"  WHERE "family_trees"."user_id" = $1 LIMIT 1  [["user_id", 3]]
  Connection Load (2.0ms)  SELECT "connections".* FROM "connections"  WHERE "connections"."invited_user_id" = $1  ORDER BY "connections"."created_at" DESC  [["invited_user_id", 3]]
  Connection Load (1.8ms)  SELECT "connections".* FROM "connections"  WHERE "connections"."inviter_user_id" = $1  ORDER BY "connections"."created_at" DESC  [["inviter_user_id", 3]]
  Connection Load (2.2ms)  SELECT "connections".* FROM "connections"  WHERE (connections.invited_user_id = 3 OR connections.inviter_user_id = 3) AND "connections"."request_status" = 0  ORDER BY "connections"."created_at" DESC
  Rendered connections/index.html.erb within layouts/connections (0.3ms)
  Rendered connections/_header.html.erb (2.8ms)
  Rendered shared/_navbar.html.erb (61.2ms)
  Rendered shared/_footer.html.erb (3.2ms)
  Rendered layouts/application.html.erb (1142.4ms)
Completed 200 OK in 1184ms (Views: 1155.5ms | ActiveRecord: 10.4ms)

修改2

这是该控制器的索引操作。

  def index
    params[:request_status] = "pending" if params[:request_status].nil?
    @connections = current_user.all_connections.where(request_status: params[:request_status]).order(created_at: :desc).group_by { |c| c.created_at.to_date }
  end

奇怪的是，对于我点击的每个操作都应该发送正确的request_status，它仍会使用request_status = 0发送SQL。

我注释掉了控制器中的params[:request_status] = setter，看看是不是这样做了，但事实并非如此。

可能导致此问题的原因是什么？

以下是另一个不同状态的日志：

Started GET "/connections?request_status=rejected" for 127.0.0.1 at 2016-01-04 21:30:29 -0500
Processing by ConnectionsController#index as HTML
  Parameters: {"request_status"=>"rejected"}
  User Load (2.2ms)  SELECT  "users".* FROM "users"  WHERE "users"."id" = 3  ORDER BY "users"."id" ASC LIMIT 1
  FamilyTree Load (1.5ms)  SELECT  "family_trees".* FROM "family_trees"  WHERE "family_trees"."user_id" = $1 LIMIT 1  [["user_id", 3]]
  Connection Load (1.4ms)  SELECT "connections".* FROM "connections"  WHERE "connections"."invited_user_id" = $1  ORDER BY "connections"."created_at" DESC  [["invited_user_id", 3]]
  Connection Load (1.0ms)  SELECT "connections".* FROM "connections"  WHERE "connections"."inviter_user_id" = $1  ORDER BY "connections"."created_at" DESC  [["inviter_user_id", 3]]
  Connection Load (1.2ms)  SELECT "connections".* FROM "connections"  WHERE (connections.invited_user_id = 3 OR connections.inviter_user_id = 3) AND "connections"."request_status" = 0  ORDER BY "connections"."created_at" DESC
  Rendered connections/index.html.erb within layouts/connections (0.2ms)
  Rendered connections/_header.html.erb (2.5ms)
  Rendered shared/_navbar.html.erb (60.3ms)
  Rendered shared/_footer.html.erb (3.0ms)
  Rendered layouts/application.html.erb (1103.8ms)
Completed 200 OK in 1130ms (Views: 1112.5ms | ActiveRecord: 7.3ms)

Answer 1

您可以使用Connection.request_statuses["pending"]获取0。

因此，您可以在查询中使用字符串，如下所示：

@connections = current_user.all_connections.where(request_status: Connection.request_statuses[params[:request_status]])

如何使用字符串而不是序数值对枚举属性执行where查询？

1 个答案: