在Phoenix Framework中显示来自RethinkDB的表数据 [英] Display table data from RethinkDB in Phoenix Framework

问题描述

我正在尝试显示RethinkDB中数据库中的数据(使用Hamiltop中的rethinkdb-elixir包 https凤凰城的://://github.com/hamiltop/rethinkdb-elixir ).我对这两个都比较陌生，但是我已经设法在两个表中插入了两个表和一些数据.我知道这一点是因为我通过RethinkDB的Web GUI对其进行了检查.

I'm attempting to display data from my databases in RethinkDB (using the rethinkdb-elixir package from Hamiltop https://github.com/hamiltop/rethinkdb-elixir) in Phoenix. I'm relatively new to both, but I already managed to insert two tables and some data into those tables. I know this because I checked it through RethinkDB's web GUI.

现在，我想在项目的html页面中显示表数据. 我已将错误减少为一个:

Now I want to display table data in an html page of my project. I've reduced the errors to one:

protocol Phoenix.HTML.Safe not implemented for %RethinkDB.Collection{data: [%{"first_name" => "Carlos", "id" => "4be8adc3-0973-45dc-bdb8-7a4dac6528d5", "last_name" => "Santos"}, %{"first_name" => "Carlos", "id" => "c84658fc-e4a4-4cb6-8107-b011ca996abd", "last_name" => "Santos"}, %{"first_name" => "Carlos", "id" => "c09fe081-379a-4334-97a3-31c5503c8c61", "last_name" => "Santos"}, %{"first_name" => "Carlos", "id" => "cf0c0ad3-3152-40f0-b613-5b051a314b51", "last_name" => "Santos"}, %{"first_name" => "Carlos", "id" => "ca28a714-ed54-4ebd-8707-d53170ead0f7", "last_name" => "Santos"}, %{"first_name" => "Carlos", "id" => "1ea77c0f-538c-4663-be92-499f16996594", "last_name" => "Santos"}, %{"first_name" => "Carlos", "id" => "1ea74846-0860-4ae5-95f5-674860cf7fc6", "last_name" => "Santos"}]}

很明显，它正在从表中提取所有插入的Carlos Santos人员(我也必须防止，但这不是我的主要问题)，但是在将其检索到Phoenix项目时出错.

Clearly it is fetching all the inserted Carlos Santos persons from the table (which I also must prevent but that is not my main issue) but having an error retrieving them to my Phoenix project.

我有一个索引页，在其中创建表和数据的控制器. 然后我添加了一个新页面: router.ex :

I've got an index page in whose controller I create the tables and data. Then I added a new page: router.ex:

get "/users", UsersController, :users

/views/users_view.ex :

defmodule RethinkExample.UsersView do
  use RethinkExample.Web, :view
end

users.html.eex :

<div class="jumbotron">
  <p><%= @users %>!</p>
</div>

users_controller.ex

defmodule RethinkExample.UsersController do
  use RethinkExample.Web, :controller
  use RethinkDB.Query

    def users(conn, _params) do
        q = table("users")
            |> filter(%{last_name: "Santos"})
            |> RethinkExample.Database.run
        |> IO.inspect
        render conn, "users.html", users: q
    end

结束

我推断html代码也不正确，因为这是我将在html标签内显示特定于路由的ID的方式. 如何成功获取数据，然后将其显示在html标签中?

I deduce that the html code is also incorrect, because this is how I would display the route specific id inside the html tags. How can I fetch the data successfully and then display it in a html tag?

推荐答案

此处的问题是@users中的数据结构为%RethinkDB.Collection{}类型(

The problem here is that your data structure in @users is of type %RethinkDB.Collection{} (source) which cannot be output using <%=...%>

您可能希望遍历用户以输出它们.像这样:

You will likely want to iterate over your users to output them. Something like:

<%= for user <- @users.data do %>
  <p><%= "#{user["first_name"]} #{user["last_name"]}" %>!</p>
<% end %>

在这里，我们使用列表理解来遍历@users.data数组.这是在EEx中输出一系列元素(例如用户，博客文章，评论等)的常用方法.

Here we are using a list comprehension to iterate over all the items on the @users.data array. This is a common way to output an array of elements (such as users, blog posts, comments, etc.) in EEx.

您可能还想考虑将q.data传递为@users而不是q，以防止必须执行@users.data.

You might also want to consider passing q.data though as @users instead of q to prevent having to do @users.data.

顺便说一句，您还可以在列表推导中使用模式匹配:

As an aside, you can also use pattern matching inside the list comprehension:

<%= for %{"first_name" => first_name, "last_name" => last_name} <- @users.data do %>
  <p><%= "#{first_name} #{last_name}" %>!</p>
<% end %>

如果您不打算使用地图中的许多字段，这将很有用.

This is useful if you don't plan on using many of the fields in the map.

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