examples/bulk_transform.js

// Licensed under the Apache License, Version 2.0 (the 'License'); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an 'AS IS' BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

const db = require('nano')('http://localhost:5984/emails')
const async = require('async')

function updateRow (row, cb) {
  var doc = row.doc
  delete doc.subject
  db.insert(doc, doc._id, function (err, data) {
    if (err) { console.log('err at ' + doc._id); cb(err) } else { console.log('updated ' + doc._id); cb() }
  })
}

function list (offset) {
  var ended = false
  offset = offset || 0
  db.list({ include_docs: true, limit: 10, skip: offset },
    function (err, data) {
      var total, offset, rows
      if (err) { console.log('fuuuu: ' + err.message); rows = []; return }
      total = data.total_rows
      offset = data.offset
      rows = data.rows
      if (offset === total) {
        ended = true
        return
      }
      async.forEach(rows, updateRow, function (err) {
        if (err) { console.log('something failed, check logs') }
        if (ended) { return }
        list(offset + 10)
      })
    })
}

list()