{"id":48040,"date":"2023-09-02T18:01:58","date_gmt":"2023-02-19T18:59:18","guid":{"rendered":"https:\/\/www.silicloud.com\/zh\/blog\/%e7%94%a8elixir-phoenix%e7%9a%84graphql%e5%ba%93-absinthe%e5%ae%9e%e7%8e%b0%e5%88%b0%e4%bd%bf%e7%94%a8connection\/"},"modified":"2024-01-15T12:29:47","modified_gmt":"2024-01-15T04:29:47","slug":"%e7%94%a8elixir-phoenix%e7%9a%84graphql%e5%ba%93-absinthe%e5%ae%9e%e7%8e%b0%e5%88%b0%e4%bd%bf%e7%94%a8connection","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/zh\/blog\/%e7%94%a8elixir-phoenix%e7%9a%84graphql%e5%ba%93-absinthe%e5%ae%9e%e7%8e%b0%e5%88%b0%e4%bd%bf%e7%94%a8connection\/","title":{"rendered":"\u7528Elixir Phoenix\u7684GraphQL\u5e93 – Absinthe\u5b9e\u73b0\u5230\u4f7f\u7528Connection"},"content":{"rendered":"

\u9996\u5148<\/h1>\n

\u5728Elixir\u7684Web\u6846\u67b6Phoenix\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u540d\u4e3aAbsinthe\u7684\u5e93\u6765\u8f7b\u677e\u5b9a\u4e49\u548c\u5b9e\u73b0GraphQL\u7684Schema\u548cType\u7b49\u3002\u7136\u800c\uff0c\u5728\u5b9e\u73b0GraphQL\u7684\u5206\u9875\u529f\u80fd\u65f6\uff0c\u5173\u4e8eConnection\u7684\u5b9e\u73b0\u65b9\u6cd5\u65e5\u8bed\u6587\u6863\u5e76\u4e0d\u591a\uff0c\u56e0\u6b64\u6211\u6253\u7b97\u603b\u7ed3\u4e00\u4e0b\u3002\u65e2\u7136\u5982\u6b64\uff0c\u6211\u5c06\u4e00\u5e76\u4ecb\u7ecdAbsinthe\u7684\u4f7f\u7528\uff08\u4e0d\u5305\u62ecMutation\u7684\u5b9e\u73b0\uff09\u3002<\/p>\n

\u987a\u4fbf\u63d0\u4e00\u4e0b\uff0c\u672c\u6587\u4e0d\u4f1a\u5bf9GraphQL\u8fdb\u884c\u89e3\u91ca\u3002\u5982\u679c\u60f3\u4e86\u89e3GraphQL\u7684\u542b\u4e49\uff0c\u8bf7\u53c2\u8003\u4ee5\u4e0b\u7f51\u7ad9\u7b49\u8d44\u6599\u3002 GraphQL\u4ecb\u7ecd\u3002<\/p>\n

\u73af\u5883<\/h1>\n

Elixir 1.7.3 \u548c Phoenix 1.4.0<\/p>\n

\u6211\u5011\u5c07\u6839\u64da\u4ee5\u4e0b\u7684\u80cc\u666f\u689d\u4ef6\u9032\u884c\u5be6\u65bd\u3002<\/p>\n

defmodule<\/span> BlogApp<\/span>.<\/span>Blogs<\/span> do<\/span>\r\n  @moduledoc<\/span> \"\"\"\r\n  The Blogs context.\r\n  \"\"\"<\/span>\r\n\r\n  import<\/span> Ecto<\/span>.<\/span>Query<\/span>,<\/span> warn:<\/span> false<\/span>\r\n  alias<\/span> BlogApp<\/span>.<\/span>Repo<\/span>\r\n\r\n  alias<\/span> BlogApp<\/span>.<\/span>Blogs<\/span>.<\/span>Post<\/span>\r\n\r\n  def<\/span> list_posts_query<\/span> do<\/span>\r\n    Post<\/span>\r\n    |><\/span> order_by<\/span>(<\/span>desc:<\/span> :inserted_at<\/span>)<\/span>\r\n  end<\/span>\r\n\r\n  def<\/span> get_post<\/span>(<\/span>id<\/span>),<\/span> do<\/span>:<\/span> Repo<\/span>.<\/span>get<\/span>(<\/span>Post<\/span>,<\/span> id<\/span>)<\/span>\r\nend<\/span>\r\n<\/code><\/pre>\n
defmodule<\/span> BlogApp<\/span>.<\/span>Blogs<\/span>.<\/span>Post<\/span> do<\/span>\r\n  use<\/span> Ecto<\/span>.<\/span>Schema<\/span>\r\n  import<\/span> Ecto<\/span>.<\/span>Changeset<\/span>\r\n\r\n  schema<\/span> \"posts\"<\/span> do<\/span>\r\n    field<\/span> :body<\/span>,<\/span> :string<\/span>\r\n    field<\/span> :image<\/span>,<\/span> :string<\/span>\r\n    field<\/span> :title<\/span>,<\/span> :string<\/span>\r\n\r\n    timestamps<\/span>()<\/span>\r\n  end<\/span>\r\n\r\n  @doc<\/span> false<\/span>\r\n  def<\/span> changeset<\/span>(<\/span>post<\/span>,<\/span> attrs<\/span>)<\/span> do<\/span>\r\n    post<\/span>\r\n    |><\/span> cast<\/span>(<\/span>attrs<\/span>,<\/span> [<\/span>:title<\/span>,<\/span> :body<\/span>,<\/span> :image<\/span>])<\/span>\r\n    |><\/span> validate_required<\/span>([<\/span>:title<\/span>,<\/span> :body<\/span>])<\/span>\r\n  end<\/span>\r\nend<\/span>\r\n\r\n<\/code><\/pre>\n
\u5b89\u88c5\u5e93<\/h1>\n
\u5c06\u4ee5\u4e0b\u7684\u5e93\u6dfb\u52a0\u5230mix.exs\u6587\u4ef6\u7684deps\u4e2d\u3002<\/p>\n
{<\/span>:absinthe<\/span>,<\/span> \"~> 1.4.0\"<\/span>},<\/span>\r\n{<\/span>:absinthe_plug<\/span>,<\/span> \"~> 1.4.0\"<\/span>},<\/span>\r\n{<\/span>:poison<\/span>,<\/span> \"~> 3.1.0\"<\/span>},<\/span>\r\n{<\/span>:absinthe_relay<\/span>,<\/span> \"~> 1.4\"<\/span>},<\/span>\r\n<\/code><\/pre>\n
absinthe\u548cabsinthe_plug\u662f\u57fa\u672c\u5b9e\u73b0\u6240\u9700\u7684\u7ec4\u4ef6\uff0cpoison\u662f\u5fc5\u8981\u7684\u5e93\uff0c\u7528\u4e8e\u5b9a\u4e49GraphQL Connection\u3002absinthe_relay\u5219\u662f\u7528\u6765\u5b9a\u4e49GraphQL Connection\u6240\u9700\u8981\u7684\u5e93\u3002<\/p>\n
\u5f53\u8fdb\u884c\u8ffd\u52a0\u64cd\u4f5c\u540e\uff0c\u6267\u884cmix deps.get\u547d\u4ee4\u3002
\n\u8fd9\u6837\u5c31\u5b8c\u6210\u4e86\u5e93\u7684\u51c6\u5907\u5de5\u4f5c\u3002<\/p>\n
Types\u7684\u5b9e\u73b0<\/h1>\n
\u4ece\u8fd9\u91cc\u5f00\u59cb\u5b9e\u9645\u8fdb\u884cGraphQL\u7684\u5b9e\u73b0\u3002
\nGraphQL\u7684\u5b9e\u73b0\u5c06\u5728\/lib\/blog_app_web\/blogs\/\u4e0b\u8fdb\u884c\u3002<\/p>\n
\u9996\u5148\uff0c\u6211\u5011\u5c07\u5be6\u73feTypes\u3002\u5be6\u73fe\u5c07\u5206\u5225\u91dd\u5c0dPost\u548cPost\u7684\u9023\u63a5(Connection)\u5169\u7a2e\u60c5\u6cc1\u9032\u884c\u3002
\n\u7531\u65bcTypes\u4e2d\u5305\u542b\u4e0d\u540c\u7a2e\u985e\u7684Object Types\u548cScalar Types\u7b49\u591a\u500b\u985e\u578b\uff0c\u6211\u5011\u5c07\u6309\u7167\u9019\u4e9b\u985e\u578b\u5206\u5272\u76ee\u9304\uff0c
\n\u5728types.ex\u6587\u4ef6\u4e2d\u5c07\u5b83\u5011\u6574\u5408\u5728\u4e00\u8d77\u3002<\/p>\n
\u7531\u4e8e\u8fd9\u6b21\u7684\u5b9e\u65bd\u662f\u53ef\u901a\u8fc7\u5bf9\u8c61\u7c7b\u578b\uff08Object Type\uff09\u5b9a\u4e49\u7684\uff0c\u56e0\u6b64\u5c06\u6309\u7167\u4ee5\u4e0b\u65b9\u5f0f\u8fdb\u884c\u5b9e\u65bd\u3002<\/p>\n
defmodule<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Objects<\/span>.<\/span>Post<\/span> do<\/span>\r\n  defmacro<\/span> __using__<\/span>(<\/span>_<\/span>)<\/span> do<\/span>\r\n    quote<\/span> do<\/span>\r\n      object<\/span> :post<\/span> do<\/span>\r\n        field<\/span> :id<\/span>,<\/span> non_null<\/span>(<\/span>:id<\/span>)<\/span>\r\n        field<\/span> :title<\/span>,<\/span> non_null<\/span>(<\/span>:string<\/span>)<\/span>\r\n        field<\/span> :body<\/span>,<\/span> non_null<\/span>(<\/span>:string<\/span>)<\/span>\r\n        field<\/span> :image<\/span>,<\/span> :string<\/span>\r\n        field<\/span> :inserted_at<\/span>,<\/span> non_null<\/span>(<\/span>:naive_datetime<\/span>)<\/span>\r\n      end<\/span>\r\n\r\n      connection<\/span>(<\/span>node_type:<\/span> :post<\/span>)<\/span>\r\n    end<\/span>\r\n  end<\/span>\r\nend<\/span>\r\n<\/code><\/pre>\n
defmodule<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Objects<\/span> do<\/span>\r\n  alias<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Objects<\/span>\r\n\r\n  defmacro<\/span> __using__<\/span>(<\/span>_<\/span>)<\/span> do<\/span>\r\n    quote<\/span> do<\/span>\r\n      use<\/span> Objects<\/span>.<\/span>Post<\/span>\r\n    end<\/span>\r\n  end<\/span>\r\nend<\/span>\r\n<\/code><\/pre>\n
objects.ex\u7684\u529f\u80fd\u662f\u5c06\u5b9e\u73b0\u4e86\u7684Object Type\u96c6\u5408\u5728\u4e00\u8d77\u3002<\/p>\n
\u5177\u4f53\u5730\u6765\u8bf4\uff0c\u5b9a\u4e49\u4e86post.ex\u4e2d\u7684Post\u548cPost Connection\u3002
\n\u5728\u5f15\u7528\u5185\u7684\u7b2c\u4e00\u4e2a\u5757\u4e2d\u5b9a\u4e49\u4e86post\u3002
\n\u53e6\u5916\uff0cconnection(node_type: :post)\u662fConnection\u7684\u5b9a\u4e49\u3002
\n\u8fd9\u6837\uff0cPost\u548cPost Connection\u7684\u5b9e\u73b0\u5c31\u5b8c\u6210\u4e86\u3002<\/p>\n
\u4ee5\u4e0b\u662f\u6211\u4eec\u6700\u540e\u5b9e\u65bd\u7684Object Type\u7684\u603b\u7ed3\uff1a<\/p>\n
defmodule<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Types<\/span> do<\/span>\r\n  use<\/span> Absinthe<\/span>.<\/span>Schema<\/span>.<\/span>Notation<\/span>\r\n  use<\/span> Absinthe<\/span>.<\/span>Relay<\/span>.<\/span>Schema<\/span>.<\/span>Notation<\/span>,<\/span> :modern<\/span>\r\n  use<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Objects<\/span>\r\nend<\/span>\r\n<\/code><\/pre>\n
Types\u7684\u5b9e\u73b0\u5df2\u7ecf\u5b8c\u6210\u4e86\u3002<\/p>\n
Schema\u7684\u5b9e\u73b0<\/h1>\n
\u5c06\u5b9e\u9645\u67e5\u8be2\u7684field\u5728Schema\u4e2d\u5b9e\u73b0\u3002
\n\u8fd9\u6b21\u6211\u4eec\u60f3\u8981\u5b9a\u4e49\u7684\u662f<\/p>\n
    \n
  1. \n
      \u5e16\u5b50<\/ol>\n<\/li>\n<\/ol>\n
       <\/p>\n
        \u5e16\u5b50\u8fde\u63a5<\/ol>\n
        \u4ee5\u4e0b\u662f\u4e24\u4e2a\u9009\u9879\u3002\u8fd9\u4e9b\u5b9a\u4e49\u53ef\u4ee5\u5b9e\u73b0\u4e3a\u4e0b\u9762\u8fd9\u6837\u3002<\/p>\n
        defmodule<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Schema<\/span> do<\/span>\r\n  use<\/span> Absinthe<\/span>.<\/span>Schema<\/span>\r\n  use<\/span> Absinthe<\/span>.<\/span>Relay<\/span>.<\/span>Schema<\/span>,<\/span> :modern<\/span>\r\n\r\n  import_types<\/span>(<\/span>BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Types<\/span>)<\/span>\r\n  import_types<\/span>(<\/span>Absinthe<\/span>.<\/span>Type<\/span>.<\/span>Custom<\/span>)<\/span>\r\n\r\n  alias<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Resolvers<\/span>\r\n  alias<\/span> Absinthe<\/span>.<\/span>Relay<\/span>.<\/span>Connection<\/span>\r\n\r\n  query<\/span> do<\/span>\r\n    @desc<\/span> \"Get posts connection\"<\/span>\r\n    connection<\/span> field<\/span> :posts<\/span>,<\/span> node_type:<\/span> :post<\/span> do<\/span>\r\n      resolve<\/span>(<\/span>&<\/span>Resolvers<\/span>.<\/span>Post<\/span>.<\/span>posts_connection<\/span>\/<\/span>2<\/span>)<\/span>\r\n    end<\/span>\r\n\r\n    @desc<\/span> \"Get a post of the blog\"<\/span>\r\n    field<\/span> :post<\/span>,<\/span> :post<\/span> do<\/span>\r\n      arg<\/span>(<\/span>:id<\/span>,<\/span> non_null<\/span>(<\/span>:id<\/span>))<\/span>\r\n      resolve<\/span>(<\/span>&<\/span>Resolvers<\/span>.<\/span>Post<\/span>.<\/span>find_post<\/span>\/<\/span>3<\/span>)<\/span>\r\n    end<\/span>\r\n  end<\/span>\r\nend<\/span>\r\n<\/code><\/pre>\n
        \u901a\u8fc7Connection.from_query\u6267\u884cSQL\u67e5\u8be2\u3002\u8fd9\u4e2a\u65b9\u6cd5\u4f1a\u6839\u636eGraphQL\u67e5\u8be2\u53c2\u6570\u4e2d\u7684first\u3001before\u7b49\u6e38\u6807\u6307\u793a\u81ea\u52a8\u6dfb\u52a0LIMIT\u548cOFFSET\u5230SQL\u67e5\u8be2\u4e2d\uff0c\u5e76\u5c06\u8fd4\u56de\u503c\u683c\u5f0f\u5316\u4e3aConnection\u7684\u6570\u636e\u683c\u5f0f\u3002<\/p>\n
        \u73b0\u5728Schema\u7684\u5b9e\u73b0\u5df2\u7ecf\u5b8c\u6210\u4e86\u3002<\/p>\n
        \u89e3\u6790\u5668\u7684\u5b9e\u73b0<\/h1>\n
        \u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u5c06\u8fdb\u884cResolvers\u7684\u5b9e\u73b0\u3002
        \n\u6211\u4eec\u8981\u5b9e\u73b0\u7684\u662f\u5728schema.ex\u4e2d\u8c03\u7528\u7684\u4e24\u4e2a\u51fd\u6570\uff1aposts_connection\u548cfind_post\u3002
        \n\u5b9e\u73b0\u8fd9\u4e9b\u4e4b\u540e\uff0c\u5c06\u4f1a\u5f97\u5230\u4ee5\u4e0b\u7ed3\u679c\u3002<\/p>\n
        defmodule<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Resolvers<\/span>.<\/span>Post<\/span> do<\/span>\r\n  alias<\/span> Absinthe<\/span>.<\/span>Relay<\/span>.<\/span>Connection<\/span>\r\n  alias<\/span> BlogApp<\/span>.<\/span>Repo<\/span>\r\n  alias<\/span> BlogApp<\/span>.<\/span>Blogs<\/span>\r\n\r\n  def<\/span> posts_connection<\/span>(<\/span>pagination_args<\/span>,<\/span> _scope<\/span>)<\/span> do<\/span>\r\n    Blogs<\/span>.<\/span>list_posts_query<\/span>()<\/span>\r\n    |><\/span> Connection<\/span>.<\/span>from_query<\/span>(<\/span>&<\/span>Repo<\/span>.<\/span>all<\/span>\/<\/span>1<\/span>,<\/span> pagination_args<\/span>)<\/span>\r\n  end<\/span>\r\n\r\n  def<\/span> find_post<\/span>(<\/span>_parent<\/span>,<\/span> %{<\/span>id:<\/span> id<\/span>},<\/span> _resolution<\/span>)<\/span> do<\/span>\r\n    case<\/span> Blogs<\/span>.<\/span>get_post<\/span>(<\/span>id<\/span>)<\/span> do<\/span>\r\n      nil<\/span> -><\/span>\r\n        {<\/span>:error<\/span>,<\/span> \"Post ID <\/span>#{<\/span>id<\/span>}<\/span> not found\"<\/span>}<\/span>\r\n\r\n      post<\/span> -><\/span>\r\n        {<\/span>:ok<\/span>,<\/span> post<\/span>}<\/span>\r\n    end<\/span>\r\n  end<\/span>\r\nend<\/span>\r\n<\/code><\/pre>\n
        \u8fd9\u6837\uff0cResolvers\u7684\u5b9e\u73b0\u5df2\u7ecf\u5b8c\u6210\u4e86\u3002
        \n\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5177\u4f53\u7684\u903b\u8f91\u5728Context\u4e2d\uff0c\u6240\u4ee5\u6211\u4eec\u901a\u8fc7\u8c03\u7528\u5b83\u4eec\u6765\u8fdb\u884c\u5b9e\u73b0\u3002<\/p>\n
        \u4f7f\u5176\u4f5c\u4e3aAPI\u53ef\u8c03\u7528<\/h1>\n
        \u5728\u4e4b\u524d\u7684\u90e8\u5206\u4e2d\uff0cGraphQL\u7684\u5b9e\u73b0\u5df2\u7ecf\u5b8c\u6210\u4e86\u3002\u6700\u540e\u6211\u4eec\u9700\u8981\u5c06\u5176\u4f5c\u4e3aAPI\u8c03\u7528\u3002
        \n\u8fde\u63a5\u5230\u8bf7\u6c42\u5f88\u7b80\u5355\uff0c\u53ea\u9700\u8981\u5728router.ex\u6587\u4ef6\u4e2d\u5b9e\u73b0\u4ee5\u4e0b\u5185\u5bb9\u3002<\/p>\n
        \u2026<\/span>\r\n  scope<\/span> \"\/api\"<\/span> do<\/span>\r\n    pipe_through<\/span> :api<\/span>\r\n    forward<\/span> \"\/graph\"<\/span>,<\/span> Absinthe<\/span>.<\/span>Plug<\/span>,<\/span> schema:<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Schema<\/span>\r\n  end<\/span>\r\n\u2026<\/span>\r\n<\/code><\/pre>\n
        \u60a8\u53ef\u4ee5\u5c06 \/api\/graph \u4f5c\u4e3aGraphQL\u8bf7\u6c42\u7684\u7aef\u70b9\u3002<\/p>\n
        \u989d\u5916\u4fe1\u606f\uff1a\u5141\u8bb8\u5728\u8fde\u63a5\u67e5\u8be2\u4e2d\u6307\u5b9a\u504f\u79fb\u91cf<\/h1>\n
        \u6700\u5f8c\u6211\u6703\u544a\u8a34\u4f60\u4e00\u7a2e\u65b9\u6cd5\uff0c\u53ef\u4ee5\u5728Connection\u67e5\u8a62\u4e2d\u6307\u5b9a\u504f\u79fb\u91cf\u7684\u9078\u9805\u3002<\/p>\n
        \u5728GraphQL\u7684Connection\u67e5\u8be2\u4e2d\uff0c\u901a\u8fc7\u4f20\u9012\u4ee5\u4e0b\u53c2\u6570\u6765\u6307\u5b9a\u8981\u68c0\u7d22\u7684\u6570\u636e\u3002<\/p>\n
          \n
        1. \n
            \u9996\u5148<\/ol>\n<\/li>\n<\/ol>\n
             <\/p>\n
              \n
            1. \n
                \u6700\u540e<\/ol>\n<\/li>\n<\/ol>\n
                 <\/p>\n
                  \n
                1. \n
                    \u4e4b\u524d<\/ol>\n<\/li>\n<\/ol>\n
                     <\/p>\n
                      \u4e4b\u540e<\/ol>\n
                      \u8fd9\u4e9b\u6982\u5ff5\u88ab\u7528\u4e8e\u5149\u6807\uff0c\u5e76\u4e14\u7531\u4e8e\u53ea\u8fdb\u884c\u7b80\u5355\u7684\u5206\u9875\u53ef\u80fd\u4f1a\u6709\u4e9b\u590d\u6742\uff0c\u6240\u4ee5\u6211\u4eec\u8fd8\u5141\u8bb8\u4f7f\u7528\u504f\u79fb\u91cf\u53c2\u6570\u3002\u53c2\u8003\uff1a\u5149\u6807\u548c\u504f\u79fb\u91cf\u7684\u8bf4\u660e<\/p>\n
                      Absinthe.Relay.Connection\u4e2d\u6709\u4e00\u4e2a\u540d\u4e3aoffset_to_cursor\u7684\u65b9\u6cd5\u3002\u8be5\u65b9\u6cd5\u5c06\u4f20\u5165\u7684\u503c\u8f6c\u6362\u4e3a\u504f\u79fb\u91cf\uff0c\u5e76\u8f6c\u6362\u4e3a\u5c3e\u6e38\u6807\uff08End Cursor\uff09\u3002\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e2a\u65b9\u6cd5\u6765\u4fee\u6539schema.ex\u5982\u4e0b\u3002<\/p>\n
                      defmodule<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Schema<\/span> do<\/span>\r\n  use<\/span> Absinthe<\/span>.<\/span>Schema<\/span>\r\n  use<\/span> Absinthe<\/span>.<\/span>Relay<\/span>.<\/span>Schema<\/span>,<\/span> :modern<\/span>\r\n\r\n  import_types<\/span>(<\/span>BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Types<\/span>)<\/span>\r\n  import_types<\/span>(<\/span>Absinthe<\/span>.<\/span>Type<\/span>.<\/span>Custom<\/span>)<\/span>\r\n\r\n  alias<\/span> BlogAppWeb<\/span>.<\/span>Blogs<\/span>.<\/span>Resolvers<\/span>\r\n  alias<\/span> Absinthe<\/span>.<\/span>Relay<\/span>.<\/span>Connection<\/span>\r\n\r\n  query<\/span> do<\/span>\r\n    @desc<\/span> \"Get all posts\"<\/span>\r\n    connection<\/span> field<\/span> :posts<\/span>,<\/span> node_type:<\/span> :post<\/span> do<\/span>\r\n      arg<\/span>(<\/span>:offset<\/span>,<\/span> :integer<\/span>)<\/span>\r\n      resolve<\/span>(<\/span>&<\/span>Resolvers<\/span>.<\/span>Post<\/span>.<\/span>posts_connection<\/span>(<\/span>convert_offset_to_before<\/span>(<\/span>&1<\/span>),<\/span> &2<\/span>))<\/span>\r\n    end<\/span>\r\n\r\n    @desc<\/span> \"Get a post of the blog\"<\/span>\r\n    field<\/span> :post<\/span>,<\/span> :post<\/span> do<\/span>\r\n      arg<\/span>(<\/span>:id<\/span>,<\/span> non_null<\/span>(<\/span>:uuid<\/span>))<\/span>\r\n      resolve<\/span>(<\/span>&<\/span>Resolvers<\/span>.<\/span>Post<\/span>.<\/span>find_post<\/span>\/<\/span>3<\/span>)<\/span>\r\n    end<\/span>\r\n  end<\/span>\r\n\r\n  defp<\/span> convert_offset_to_before<\/span>(<\/span>pagination_args<\/span>)<\/span> do<\/span>\r\n    case<\/span> pagination_args<\/span> do<\/span>\r\n      %{<\/span>offset:<\/span> offset<\/span>}<\/span> -><\/span>\r\n        Map<\/span>.<\/span>merge<\/span>(<\/span>pagination_args<\/span>,<\/span> %{<\/span>before:<\/span> Connection<\/span>.<\/span>offset_to_cursor<\/span>(<\/span>offset<\/span>)})<\/span>\r\n\r\n      _<\/span> -><\/span>\r\n        pagination_args<\/span>\r\n    end<\/span>\r\n  end<\/span>\r\nend<\/span>\r\n<\/code><\/pre>\n
                      \u73b0\u5728\u4f60\u53ef\u4ee5\u901a\u8fc7\u4f20\u9012\u53c2\u6570\u6765\u6307\u5b9a\u504f\u79fb\u91cf\u3002<\/p>\n
                      \u6700\u540e\u7684<\/h1>\n
                      \u6211\u8ba4\u4e3aGraphQL\u7684\u4f18\u52bf\u5728\u4e8e\u4e00\u65e6\u5b9e\u73b0\u4e86\u6846\u67b6\uff0c\u5c31\u53ef\u4ee5\u7075\u6d3b\u5730\u8fdb\u884c\u5f00\u53d1\u3002
                      \n\u7136\u800c\uff0c\u7531\u4e8eGraphQL\u6709\u9488\u5bf9\u4e0d\u540c\u8bed\u8a00\u7684\u5e93\uff0c\u56e0\u6b64\u6709\u65f6\u53ef\u80fd\u4f1a\u9047\u5230\u4e00\u4e9b\u95ee\u9898\uff0c\u4f8b\u5982\u6587\u6863\u8f83\u5c11\u6216\u4e0d\u6210\u719f\u3002
                      \n\u5982\u679c\u672c\u6587\u5bf9\u4f7f\u7528Phoenix\u5b9e\u73b0GraphQL\u6709\u6240\u5e2e\u52a9\uff0c\u6211\u5c06\u975e\u5e38\u9ad8\u5174\u3002<\/p>\n
                      \u987a\u4fbf\u63d0\u4e00\u4e0b\uff0c\u6211\u4eec\u8fd9\u6b21\u4f7f\u7528\u7684\u5b9e\u73b0\u662f\u4ecehttps:\/\/github.com\/getty104\/blog_app_ex \u4e0b\u8f7d\u7684\u3002
                      \n\u8fd9\u91cc\u5305\u542b\u4e86\u6574\u4e2a\u5e94\u7528\u7a0b\u5e8f\u7684\u6240\u6709\u4ee3\u7801\uff0c\u5982\u679c\u65b9\u4fbf\u7684\u8bdd\uff0c\u8bf7\u67e5\u770b\u4e00\u4e0b\u3002<\/p>\n
                      \u6587\u732e\u5f15\u7528<\/h1>\n
                        \n
                      1. \n
                          https:\/\/hexdocs.pm\/absinthe_relay\/Absinthe.Relay.html \u53ef\u4ee5\u5728\u8fd9\u4e2a\u94fe\u63a5\u4e2d\u627e\u5230\u6709\u5173Absinthe.Relay\u7684\u6587\u6863\u3002<\/ol>\n<\/li>\n<\/ol>\n
                          https:\/\/hexdocs.pm\/absinthe\/plug-phoenix.html \u53ef\u4ee5\u5728\u8fd9\u4e2a\u94fe\u63a5\u4e2d\u627e\u5230\u5173\u4e8eAbsinthe\u5728Phoenix\u4e2d\u4f7f\u7528\u7684\u6587\u6863\u3002<\/p>\n
                          https:\/\/hexdocs.pm\/absinthe_relay\/Absinthe.Relay.Connection.html#cursor_to_offset\/1 \u53ef\u4ee5\u5728\u8fd9\u4e2a\u94fe\u63a5\u4e2d\u627e\u5230\u6709\u5173Absinthe.Relay.Connection\u7684cursor_to_offset\/1\u7684\u4fe1\u606f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
                          \u9996\u5148 \u5728Elixir\u7684Web\u6846\u67b6Phoenix\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u540d\u4e3aAbsinthe\u7684\u5e93\u6765\u8f7b\u677e\u5b9a\u4e49\u548c\u5b9e\u73b0Grap […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-48040","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"\n\u7528Elixir Phoenix\u7684GraphQL\u5e93 - Absinthe\u5b9e\u73b0\u5230\u4f7f\u7528Connection - Blog - Silicon Cloud<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/zh\/blog\/\u7528elixir-phoenix\u7684graphql\u5e93-absinthe\u5b9e\u73b0\u5230\u4f7f\u7528connection\/\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"\u7528Elixir Phoenix\u7684GraphQL\u5e93 - 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