CouchDB.md

Using DataLoader with CouchDB

CouchDB is a "NoSQL" document database which supports batch loading via the HTTP Bulk Document API, making it well suited for use with DataLoader.

This example uses the nano CouchDB client which offers a fetch method supporting the bulk document API.

const DataLoader = require('dataloader');
const nano = require('nano');

const couch = nano('http://localhost:5984');

const userDB = couch.use('users');
const userLoader = new DataLoader(
  keys =>
    new Promise((resolve, reject) => {
      userDB.fetch({ keys: keys }, (error, docs) => {
        if (error) {
          return reject(error);
        }
        resolve(
          docs.rows.map(row => (row.error ? new Error(row.error) : row.doc)),
        );
      });
    }),
);

// Usage

const promise1 = userLoader.load('8fce1902834ac6458e9886fa7f89c0ef');
const promise2 = userLoader.load('00a271787f89c0ef2e10e88a0c00048b');
const [user1, user2] = await Promise.all([promise1, promise2]);
console.log(user1, user2);