graphql/dataloader

[QUESTION] How should I paginate my data using DataLoader?

Open

#231 ouverte le 5 déc. 2019

Voir sur GitHub
 (20 commentaires) (8 réactions) (0 assignés)JavaScript (12 520 stars) (556 forks)batch import
help wanted

Description

I have the following query:

{
  user(id: $id) {
    username
    comments(last: 10) { # How can I handle pagination here?
      id
      body
      author {
        username
      }
      replies(last: 3) { # How can I handle pagination here?
        id
        body
      }
    }
  }
}

How can I handle pagination in those cases? Should I use DataLoader?

Until now, everything that I found on the web suggests using the splice array method, but if I use it, my server will run out of memory, as I should paginate the data on the SQL query, am I right?

So how I am able to query my database with such GraphQL query? Do you handle those cases in any of your projects?

I am really struggling with that. It is even possible to use DataLoader in this case? And if I not use it, I my server will suffer a lot with the N+1 problem...

Guide contributeur

Stack technique
javascriptnodejsgraphql
Domaine
backendapidatabase
Type d'issue
research
DifficultéDifficulté estimée pour un nouveau contributeur, de 1 pour un très petit changement à 5 pour un travail expert.
3
Temps estiméFourchette de temps approximative pour investiguer, implémenter, tester et préparer une pull request.
3-5 days
Statut d'activitéDisponibilité apparente de l'issue : fraîche, active, ancienne, bloquée ou en attente d'un mainteneur.
stale
ClartéClarté avec laquelle l'issue explique le changement attendu, les critères d'acceptation et la prochaine étape.
needs investigation
Prérequis
GraphQL basicsDataLoader fundamentalsSQL pagination conceptsNode.js development
Accessibilité débutantScore de 1 à 100 estimant l'accessibilité de cette issue pour un premier contributeur.
35
Direction de recherche
The issue is a question on implementing pagination with DataLoader in GraphQL. The user wants to paginate nested comments and replies efficiently. Review the comments in the issue for suggested solutions, such as using DataLoader with batched SQL queries that include LIMIT and OFFSET or keyset pagination. The repository's documentation and examples (e.g., the 'src/' directory) may also provide patterns. A concrete approach would be to create a DataLoader that loads paginated results per parent, but ensure batching works correctly by passing pagination parameters through the loader's key. The solution may require customizing DataLoader's batch function to handle different pagination arguments.