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ruby - 如何让一个字段更新/更改另一个字段？

问题描述

我想得到另一个字段解析的字段。

我有一个根据一些参数生成的列表，并想更新总字段

我的方法可能是不正确的。

显然，我试图避免重新运行相同的数据库查询并在查询字符串中向上传递过滤器级别。

因此，假设我的查询使用以下 ruby​​ 类型：

Types::PostListType = GraphQL::ObjectType.define do
    name 'PostList'

    field :total, !types.Int, default_value: 0 # <-- this is what I'd like to update in :posts resolution
    field :page, !types.Int, default_value: 0 # <-- this is what I'd like to update in :posts resolution
    field :per_page, !types.Int, default_value: 0 # <-- this is what I'd like to update in :posts resolution

    field :posts, types[Types::PostType] do
        argument :page, types.Int, default_value: 1
        argument :per_page, types.Int, default_value: 10 # <-- also need a limit here (hence why I need a field to tell what's been used in the end)
        argument :filter, types.String, default_value: ''
        resolve ->(user, *_args) {
            posts = function_to_filter(args[:filter])
            # how do I update total with posts.count here?
            posts.paginate(page: args[:page], per_page: args[:per_page])
            # how do I update per_page and page?
        }
    end

end

我的查询是这样的：

query ProspectList {
  posts(filter:"example", page: 2) {
    total
    page
    per_page
    posts {
      id
      ...
    }
  }
}

标签： rubygraphqlgraphql-ruby

解决方案

您想要的是返回带有总计、页面、每页的帖子，而无需重新运行数据库查询。

我想修改查询定义，因为posts、total、page、per_page 应该在类型中组合。

像这样：Types::PostListType

Types::PostListType = GraphQL::ObjectType.define do
  name 'PostList'

  field :total, !types.Int
  field :page, !types.Int
  field :per_page, !types.Int
  field :posts, types[Types::PostType]
end

然后在解析中返回对象，其中包含帖子、总数、页面、per_page

Types::QueryType = GraphQL::ObjectType.define do
  name "Query"

  field :postlist, Types::PostListType do
    argument :page, types.Int, default_value: 1
    argument :per_page, types.Int, default_value: 1
    argument :filter, types.String
    resolve ->(_obj, args, _ctx) {
      result = Post.paginate(page: args[:page], per_page: args[:per_page])
      Posts = Struct.new(:posts, :page, :per_page, :total)
      Posts.new(
        result,
        args[:page],
        args[:per_page],
        result.total_entries
      )
    }
  end
end

也可以定义一个对象并返回。包装器::PostList

module Wrapper
  class PostList
    attr_accessor :posts, :total, :page, :per_page
    def initialize(posts, page, per_page)
      @posts = posts
      @total = posts.total_entries
      @page = page
      @per_page = per_page
    end
  end
end

...
  field :postlist, Types::PostListType do
    argument :page, types.Int, default_value: 1
    argument :per_page, types.Int, default_value: 1
    argument :filter, types.String
    resolve ->(_obj, args, _ctx) {
      Wrapper::PostList.new(Post.paginate(page: args[:page], per_page: args[:per_page]), args[:page], args[:per_page])
    }
...

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