Class: GraphQL::Sources::ActiveRecordExists

Inherits:
ActiveRecordBase
  • Object
show all
Defined in:
lib/graphql/sources/active_record_exists.rb

Overview

A class for checking existence of records.

class Post
  has_many :likes
end

class Like
  belongs_to :post
end

class PostType < GraphQL::Schema::Object
  field :likes, Integer, null: false

  def likes
    dataloader
      .with(GraphQL::Sources::ActiveRecordExists, ::Like, key: :post_id)
      .load(object.id)
  end
end

The resulting SQL query is:

SELECT "likes"."post_id"
FROM "likes"
WHERE "likes"."post_id" IN (1, 2, 3, ...)
GROUP BY "likes"."post_id"

Instance Method Summary collapse

Methods inherited from ActiveRecordBase

batch_key_for, #initialize

Constructor Details

This class inherits a constructor from GraphQL::Sources::ActiveRecordBase

Instance Method Details

#fetch(keys) ⇒ Array<Boolean>

Returns an array of booleans.

Parameters:

  • keys (Array) —

    an array of keys

Returns:

  • (Array<Boolean>) —

    an array of booleans



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# File 'lib/graphql/sources/active_record_exists.rb', line 34

def fetch(keys)
  set = Set.new(models(keys: keys).group(@key).pluck(@key))
  keys.map { |key| set.member?(key) }
end