is loadAll operation outside of dataloader? about dataloader

[pedro-surf]

Why did you close it without a reference nor a comment? @AlicanC provided some good info about connections setup, however this didn't answer the question, for me, at least.

[jgcmarins]

ideally you should not "loadAll", but have a connection which knows how to load each individually
check this: https://github.com/entria/graphql-mongoose-loader/blob/master/src/ConnectionFromMongoCursor.ts

[zuhair-naqvi]

@jepezi do you mind please sharing your learnings here?

[AlicanC]

On a root connection's resolve(), I just query the database for ids and return objects with only ids in them ([{ id: 1 }, { id: 2 }, ...]) and then in resolveNode() (where I receive those objects) I load the rest of the data with DataLoader.

At first, making two trips to the database (one trip for ids and another batched trip for complete data) seemed stupid, but if the ids are cached then the second trip doesn't happen at all and if they are not cached then you are caching them for use in another query.

The function I use to create root connections look like this:

export function createRootConnectionField({ nodeType, tableName }) {
  const { connectionType } = connectionDefinitions({
    nodeType,
    resolveNode: (edge) => getDataLoaderOfType(nodeType).load(edge.node.id),
    connectionFields: () => ({
      totalCount: {
        type: GraphQLInt,
        resolve: (connection) => connection.totalCount,
      },
    }),
  });

  return {
    type: connectionType,
    args: connectionArgs,
    resolve: async (viewer, args) => {
      const objects = await db(tableName).select('id');

      return {
        ...connectionFromArray(objects, args),
        totalCount: objects.count,
      };
    },
  };
}

On the other hand, if your cache gets invalidated often, then you will be making two trips all the time and this becomes a performance issue. If that's the case then you could easily select all columns in resolve() and remove resolveNode(). If you do that, you might also want to prime the cache using dataLoader.prime(key, value) in your resolve().