I am writing a webapp with Node.js and mongoose. How can I paginate the results I get from a .find() call? I would like a functionality comparable to "LIMIT 50,100" in SQL.
I'm am very disappointed by the accepted answers in this question. This will not scale. If you read the fine print on cursor.skip( ):
The cursor.skip() method is often expensive because it requires the server to walk from the beginning of the collection or index to get the offset or skip position before beginning to return result. As offset (e.g. pageNumber above) increases, cursor.skip() will become slower and more CPU intensive. With larger collections, cursor.skip() may become IO bound.
To achieve pagination in a scaleable way combine a limit( ) along with at least one filter criterion, a createdOn date suits many purposes.
MyModel.find( { createdOn: { $lte: request.createdOnBefore } } )
.limit( 10 )
.sort( '-createdOn' )
After taking a closer look at the Mongoose API with the information provided by Rodolphe, I figured out this solution:
MyModel.find(query, fields, { skip: 10, limit: 5 }, function(err, results) { ... });
Pagination using mongoose, express and jade - Here's a link to my blog with more detail
var perPage = 10
, page = Math.max(0, req.params.page)
Event.find()
.select('name')
.limit(perPage)
.skip(perPage * page)
.sort({
name: 'asc'
})
.exec(function(err, events) {
Event.count().exec(function(err, count) {
res.render('events', {
events: events,
page: page,
pages: count / perPage
})
})
})
You can chain just like that:
var query = Model.find().sort('mykey', 1).skip(2).limit(5)
Execute the query using exec
query.exec(callback);
In this case, you can add the query page and/ or limit to your URL as a query string.
For example:
?page=0&limit=25 // this would be added onto your URL: http:localhost:5000?page=0&limit=25
Since it would be a String we need to convert it to a Number for our calculations. Let's do it using the parseInt method and let's also provide some default values.
const pageOptions = {
page: parseInt(req.query.page, 10) || 0,
limit: parseInt(req.query.limit, 10) || 10
}
sexyModel.find()
.skip(pageOptions.page * pageOptions.limit)
.limit(pageOptions.limit)
.exec(function (err, doc) {
if(err) { res.status(500).json(err); return; };
res.status(200).json(doc);
});
BTW
Pagination starts with 0
You can use a little package called Mongoose Paginate that makes it easier.
$ npm install mongoose-paginate
After in your routes or controller, just add :
/**
* querying for `all` {} items in `MyModel`
* paginating by second page, 10 items per page (10 results, page 2)
**/
MyModel.paginate({}, 2, 10, function(error, pageCount, paginatedResults) {
if (error) {
console.error(error);
} else {
console.log('Pages:', pageCount);
console.log(paginatedResults);
}
}
Query:
search = productName
Params:
page = 1
// Pagination
router.get("/search/:page", (req, res, next) => {
const resultsPerPage = 5;
let page = req.params.page >= 1 ? req.params.page : 1;
const query = req.query.search;
page = page - 1
Product.find({ name: query })
.select("name")
.sort({ name: "asc" })
.limit(resultsPerPage)
.skip(resultsPerPage * page)
.then((results) => {
return res.status(200).send(results);
})
.catch((err) => {
return res.status(500).send(err);
});
});
This is a example you can try this,
var _pageNumber = 2,
_pageSize = 50;
Student.count({},function(err,count){
Student.find({}, null, {
sort: {
Name: 1
}
}).skip(_pageNumber > 0 ? ((_pageNumber - 1) * _pageSize) : 0).limit(_pageSize).exec(function(err, docs) {
if (err)
res.json(err);
else
res.json({
"TotalCount": count,
"_Array": docs
});
});
});
Try using mongoose function for pagination. Limit is the number of records per page and number of the page.
var limit = parseInt(body.limit);
var skip = (parseInt(body.page)-1) * parseInt(limit);
db.Rankings.find({})
.sort('-id')
.limit(limit)
.skip(skip)
.exec(function(err,wins){
});
This is what I done it on code
var paginate = 20;
var page = pageNumber;
MySchema.find({}).sort('mykey', 1).skip((pageNumber-1)*paginate).limit(paginate)
.exec(function(err, result) {
// Write some stuff here
});
That is how I done it.
Simple and powerful pagination solution
async getNextDocs(no_of_docs_required: number = 5, last_doc_id?: string) {
let docs
if (!last_doc_id) {
// get first 5 docs
docs = await MySchema.find().sort({ _id: -1 }).limit(no_of_docs_required)
}
else {
// get next 5 docs according to that last document id
docs = await MySchema.find({_id: {$lt: last_doc_id}})
.sort({ _id: -1 }).limit(no_of_docs_required)
}
return docs
}
last_doc_id: the last document id that you get
no_of_docs_required: the number of docs that you want to fetch i.e. 5, 10, 50 etc.
If you don't provide the last_doc_id to the method, you'll get i.e. 5 latest docs
If you've provided the last_doc_id then you'll get the next i.e. 5 documents.
There are some good answers giving the solution that uses skip() & limit(), however, in some scenarios, we also need documents count to generate pagination. Here's what we do in our projects:
const PaginatePlugin = (schema, options) => {
options = options || {}
schema.query.paginate = async function(params) {
const pagination = {
limit: options.limit || 10,
page: 1,
count: 0
}
pagination.limit = parseInt(params.limit) || pagination.limit
const page = parseInt(params.page)
pagination.page = page > 0 ? page : pagination.page
const offset = (pagination.page - 1) * pagination.limit
const [data, count] = await Promise.all([
this.limit(pagination.limit).skip(offset),
this.model.countDocuments(this.getQuery())
]);
pagination.count = count;
return { data, pagination }
}
}
mySchema.plugin(PaginatePlugin, { limit: DEFAULT_LIMIT })
// using async/await
const { data, pagination } = await MyModel.find(...)
.populate(...)
.sort(...)
.paginate({ page: 1, limit: 10 })
// or using Promise
MyModel.find(...).paginate(req.query)
.then(({ data, pagination }) => {
})
.catch(err => {
})
Here is a version that I attach to all my models. It depends on underscore for convenience and async for performance. The opts allows for field selection and sorting using the mongoose syntax.
var _ = require('underscore');
var async = require('async');
function findPaginated(filter, opts, cb) {
var defaults = {skip : 0, limit : 10};
opts = _.extend({}, defaults, opts);
filter = _.extend({}, filter);
var cntQry = this.find(filter);
var qry = this.find(filter);
if (opts.sort) {
qry = qry.sort(opts.sort);
}
if (opts.fields) {
qry = qry.select(opts.fields);
}
qry = qry.limit(opts.limit).skip(opts.skip);
async.parallel(
[
function (cb) {
cntQry.count(cb);
},
function (cb) {
qry.exec(cb);
}
],
function (err, results) {
if (err) return cb(err);
var count = 0, ret = [];
_.each(results, function (r) {
if (typeof(r) == 'number') {
count = r;
} else if (typeof(r) != 'number') {
ret = r;
}
});
cb(null, {totalCount : count, results : ret});
}
);
return qry;
}
Attach it to your model schema.
MySchema.statics.findPaginated = findPaginated;
Above answer's holds good.
Just an add-on for anyone who is into async-await rather than
promise !!
const findAllFoo = async (req, resp, next) => {
const pageSize = 10;
const currentPage = 1;
try {
const foos = await FooModel.find() // find all documents
.skip(pageSize * (currentPage - 1)) // we will not retrieve all records, but will skip first 'n' records
.limit(pageSize); // will limit/restrict the number of records to display
const numberOfFoos = await FooModel.countDocuments(); // count the number of records for that model
resp.setHeader('max-records', numberOfFoos);
resp.status(200).json(foos);
} catch (err) {
resp.status(500).json({
message: err
});
}
};
you can use the following line of code as well
per_page = parseInt(req.query.per_page) || 10
page_no = parseInt(req.query.page_no) || 1
var pagination = {
limit: per_page ,
skip:per_page * (page_no - 1)
}
users = await User.find({<CONDITION>}).limit(pagination.limit).skip(pagination.skip).exec()
this code will work in latest version of mongo
A solid approach to implement this would be to pass the values from the frontend using a query string. Let's say we want to get page #2 and also limit the output to 25 results.
The query string would look like this: ?page=2&limit=25 // this would be added onto your URL: http:localhost:5000?page=2&limit=25
Let's see the code:
// We would receive the values with req.query.<<valueName>> => e.g. req.query.page
// Since it would be a String we need to convert it to a Number in order to do our
// necessary calculations. Let's do it using the parseInt() method and let's also provide some default values:
const page = parseInt(req.query.page, 10) || 1; // getting the 'page' value
const limit = parseInt(req.query.limit, 10) || 25; // getting the 'limit' value
const startIndex = (page - 1) * limit; // this is how we would calculate the start index aka the SKIP value
const endIndex = page * limit; // this is how we would calculate the end index
// We also need the 'total' and we can get it easily using the Mongoose built-in **countDocuments** method
const total = await <<modelName>>.countDocuments();
// skip() will return a certain number of results after a certain number of documents.
// limit() is used to specify the maximum number of results to be returned.
// Let's assume that both are set (if that's not the case, the default value will be used for)
query = query.skip(startIndex).limit(limit);
// Executing the query
const results = await query;
// Pagination result
// Let's now prepare an object for the frontend
const pagination = {};
// If the endIndex is smaller than the total number of documents, we have a next page
if (endIndex < total) {
pagination.next = {
page: page + 1,
limit
};
}
// If the startIndex is greater than 0, we have a previous page
if (startIndex > 0) {
pagination.prev = {
page: page - 1,
limit
};
}
// Implementing some final touches and making a successful response (Express.js)
const advancedResults = {
success: true,
count: results.length,
pagination,
data: results
}
// That's it. All we have to do now is send the `results` to the frontend.
res.status(200).json(advancedResults);
I would suggest implementing this logic into middleware so you can be able to use it for various routes/ controllers.
You can do using mongoose-paginate-v2. For more info click here
const mongoose = require('mongoose');
const mongoosePaginate = require('mongoose-paginate-v2');
const mySchema = new mongoose.Schema({
// your schema code
});
mySchema.plugin(mongoosePaginate);
const myModel = mongoose.model('SampleModel', mySchema);
myModel.paginate().then({}) // Usage
I have found a very efficient way and implemented it myself, I think this way is the best for the following reasons:
It does not use skip, which time complexity doesn't scale well;
It uses IDs to query the document. Ids are indexed by default in MongoDB, making them very fast to query;
It uses lean queries, these are known to be VERY performative, as they remove a lot of "magic" from Mongoose and returns a document that comes kind of "raw" from MongoDB;
It doesn't depend on any third party packages that might contain vulnerabilities or have vulnerable dependencies.
The only caveat to this is that some methods of Mongoose, such as .save() will not work well with lean queries, such methods are listed in this awesome blog post, I really recommend this series, because it considers a lot of aspects, such as type security (which prevents critical errors) and PUT/ PATCH.
I will provide some context, this is a Pokémon repository, the pagination works as the following: The API receives unsafeId from the req.body object of Express, we need to convert this to string in order to prevent NoSQL injections (it could be an object with evil filters), this unsafeId can be an empty string or the ID of the last item of the previous page, it goes like this:
/**
* #description GET All with pagination, will return 200 in success
* and receives the last ID of the previous page or undefined for the first page
* Note: You should take care, read and consider about Off-By-One error
* #param {string|undefined|unknown} unsafeId - An entire page that comes after this ID will be returned
*/
async readPages(unsafeId) {
try {
const id = String(unsafeId || '');
let criteria;
if (id) {
criteria = {_id: {$gt: id}};
} // else criteria is undefined
// This query looks a bit redundant on `lean`, I just really wanted to make sure it is lean
const pokemon = await PokemonSchema.find(
criteria || {},
).setOptions({lean: true}).limit(15).lean();
// This would throw on an empty page
// if (pokemon.length < 1) {
// throw new PokemonNotFound();
// }
return pokemon;
} catch (error) {
// In this implementation, any error that is not defined by us
// will not return on the API to prevent information disclosure.
// our errors have this property, that indicate
// that no sensitive information is contained within this object
if (error.returnErrorResponse) {
throw error;
} // else
console.error(error.message);
throw new InternalServerError();
}
}
Now, to consume this and avoid Off-By-One errors in the frontend, you do it like the following, considering that pokemons is the Array of Pokémons documents that are returned from the API:
// Page zero
const pokemons = await fetchWithPagination({'page': undefined});
// Page one
// You can also use a fixed number of pages instead of `pokemons.length`
// But `pokemon.length` is more reliable (and a bit slower)
// You will have trouble with the last page if you use it with a constant
// predefined number
const id = pokemons[pokemons.length - 1]._id;
if (!id) {
throw new Error('Last element from page zero has no ID');
} // else
const page2 = await fetchWithPagination({'page': id});
As a note here, Mongoose IDs are always sequential, this means that any newer ID will always be greater than the older one, that is the foundation of this answer.
This approach has been tested agaisnt Off-By-One errors, for instance, the last element of a page could be returned as the first element of the following one (duplicated), or an element that is between the last of the previous page and the first of the current page might disappear.
When you are done with all the pages and request a page after the last element (one that does not exist), the response will be an empty array with 200 (OK), which is awesome!
The easiest and more speedy way is, paginate with the objectId
Example;
Initial load condition
condition = {limit:12, type:""};
Take the first and last ObjectId from response data
Page next condition
condition = {limit:12, type:"next", firstId:"57762a4c875adce3c38c662d", lastId:"57762a4c875adce3c38c6615"};
Page next condition
condition = {limit:12, type:"next", firstId:"57762a4c875adce3c38c6645", lastId:"57762a4c875adce3c38c6675"};
In mongoose
var condition = {};
var sort = { _id: 1 };
if (req.body.type == "next") {
condition._id = { $gt: req.body.lastId };
} else if (req.body.type == "prev") {
sort = { _id: -1 };
condition._id = { $lt: req.body.firstId };
}
var query = Model.find(condition, {}, { sort: sort }).limit(req.body.limit);
query.exec(function(err, properties) {
return res.json({ "result": result);
});
The best approach (IMO) is to use skip and limit BUT within a limited collections or documents.
To make the query within limited documents, we can use specific index like index on a DATE type field. See that below
let page = ctx.request.body.page || 1
let size = ctx.request.body.size || 10
let DATE_FROM = ctx.request.body.date_from
let DATE_TO = ctx.request.body.date_to
var start = (parseInt(page) - 1) * parseInt(size)
let result = await Model.find({ created_at: { $lte: DATE_FROM, $gte: DATE_TO } })
.sort({ _id: -1 })
.select('<fields>')
.skip( start )
.limit( size )
.exec(callback)
Most easiest plugin for pagination.
https://www.npmjs.com/package/mongoose-paginate-v2
Add plugin to a schema and then use model paginate method:
var mongoose = require('mongoose');
var mongoosePaginate = require('mongoose-paginate-v2');
var mySchema = new mongoose.Schema({
/* your schema definition */
});
mySchema.plugin(mongoosePaginate);
var myModel = mongoose.model('SampleModel', mySchema);
myModel.paginate().then({}) // Usage
let page,limit,skip,lastPage, query;
page = req.params.page *1 || 1; //This is the page,fetch from the server
limit = req.params.limit * 1 || 1; // This is the limit ,it also fetch from the server
skip = (page - 1) * limit; // Number of skip document
lastPage = page * limit; //last index
counts = await userModel.countDocuments() //Number of document in the collection
query = query.skip(skip).limit(limit) //current page
const paginate = {}
//For previous page
if(skip > 0) {
paginate.prev = {
page: page - 1,
limit: limit
}
//For next page
if(lastPage < counts) {
paginate.next = {
page: page + 1,
limit: limit
}
results = await query //Here is the final results of the query.
const page = req.query.page * 1 || 1;
const limit = req.query.limit * 1 || 1000;
const skip = (page - 1) * limit;
query = query.skip(skip).limit(limit);
This is example function for getting the result of skills model with pagination and limit options
export function get_skills(req, res){
console.log('get_skills');
var page = req.body.page; // 1 or 2
var size = req.body.size; // 5 or 10 per page
var query = {};
if(page < 0 || page === 0)
{
result = {'status': 401,'message':'invalid page number,should start with 1'};
return res.json(result);
}
query.skip = size * (page - 1)
query.limit = size
Skills.count({},function(err1,tot_count){ //to get the total count of skills
if(err1)
{
res.json({
status: 401,
message:'something went wrong!',
err: err,
})
}
else
{
Skills.find({},{},query).sort({'name':1}).exec(function(err,skill_doc){
if(!err)
{
res.json({
status: 200,
message:'Skills list',
data: data,
tot_count: tot_count,
})
}
else
{
res.json({
status: 401,
message: 'something went wrong',
err: err
})
}
}) //Skills.find end
}
});//Skills.count end
}
Using ts-mongoose-pagination
const trainers = await Trainer.paginate(
{ user: req.userId },
{
perPage: 3,
page: 1,
select: '-password, -createdAt -updatedAt -__v',
sort: { createdAt: -1 },
}
)
return res.status(200).json(trainers)
Below Code Is Working Fine For Me.
You can add finding filters also and user same in countDocs query to get accurate results.
export const yourController = async (req, res) => {
const { body } = req;
var perPage = body.limit,
var page = Math.max(0, body.page);
yourModel
.find() // You Can Add Your Filters inside
.limit(perPage)
.skip(perPage * (page - 1))
.exec(function (err, dbRes) {
yourModel.count().exec(function (err, count) { // You Can Add Your Filters inside
res.send(
JSON.stringify({
Articles: dbRes,
page: page,
pages: count / perPage,
})
);
});
});
};
You can write query like this.
mySchema.find().skip((page-1)*per_page).limit(per_page).exec(function(err, articles) {
if (err) {
return res.status(400).send({
message: err
});
} else {
res.json(articles);
}
});
page : page number coming from client as request parameters.
per_page : no of results shown per page
If you are using MEAN stack following blog post provides much of the information to create pagination in front end using angular-UI bootstrap and using mongoose skip and limit methods in the backend.
see : https://techpituwa.wordpress.com/2015/06/06/mean-js-pagination-with-angular-ui-bootstrap/
You can either use skip() and limit(), but it's very inefficient. A better solution would be a sort on indexed field plus limit().
We at Wunderflats have published a small lib here: https://github.com/wunderflats/goosepage
It uses the first way.
If you are using mongoose as a source for a restful api have a look at
'restify-mongoose' and its queries. It has exactly this functionality built in.
Any query on a collection provides headers that are helpful here
test-01:~$ curl -s -D - localhost:3330/data?sort=-created -o /dev/null
HTTP/1.1 200 OK
link: </data?sort=-created&p=0>; rel="first", </data?sort=-created&p=1>; rel="next", </data?sort=-created&p=134715>; rel="last"
.....
Response-Time: 37
So basically you get a generic server with a relatively linear load time for queries to collections. That is awesome and something to look at if you want to go into a own implementation.
app.get("/:page",(req,res)=>{
post.find({}).then((data)=>{
let per_page = 5;
let num_page = Number(req.params.page);
let max_pages = Math.ceil(data.length/per_page);
if(num_page == 0 || num_page > max_pages){
res.render('404');
}else{
let starting = per_page*(num_page-1)
let ending = per_page+starting
res.render('posts', {posts:data.slice(starting,ending), pages: max_pages, current_page: num_page});
}
});
});
I am trying to call one async function from inside a loop run by another async function. These functions call APIs and I am using request-promise using nodeJS.
functions.js file
const rp = require("request-promise");
// function (1)
async email_views: emailId => {
let data = {};
await rp({
url: 'myapiurl',
qs: { accessToken: 'xyz', emailID: emailId },
method: 'GET'
})
.then( body => { data = JSON.parse(body) })
.catch( error => { console.log(error} );
return data;
};
The above JSON looks like this:
...
data:{
records: [
{
...
contactID: 123456,
...
},
{
...
contactID: 456789,
...
}
]
}
...
I am running a loop to get individual record, where I am getting a contactID associated with each of them.
// function#2 (also in functions.js file)
async contact_detail: contactId => {
let data = {};
await rp({
url: 'myapiurl2',
qs: { accessToken: 'xyz', contactID: contactId },
method: 'GET'
})
.then( body => { data = JSON.parse(body) })
.catch( error => { console.log(error} );
return data;
};
The above function takes one contactId as parameter and gets that contact's detail calling another API endpoint.
Both functions work fine when they are called separately. But I am trying to do it inside a loop like this:
...
const result = await email_views(99999); // function#1
const records = result.data.records;
...
let names = "";
for( let i=0; i<records.length; i++) {
...
const cId = records[i].contactID;
const contact = await contact_detail(cId); // function#2
names += contact.data.firstName + " " + contact.data.lastName + " ";
...
}
console.log(names);
...
The problem is I am only getting the first contact back from the above code block, i.e. even I have 20 records from function#1, in the loop when I am calling contact_detail (function#2) for each contactID (cId), I get contact detail once, i.e. for the first cId only. For rest I get nothing!
What is the correct way to achieve this using nodeJs?
UPDATE:
const { App } = require("jovo-framework");
const { Alexa } = require("jovo-platform-alexa");
const { GoogleAssistant } = require("jovo-platform-googleassistant");
const { JovoDebugger } = require("jovo-plugin-debugger");
const { FileDb } = require("jovo-db-filedb");
const custom = require("./functions");
const menuop = require("./menu");
const stateus = require("./stateus");
const alexaSpeeches = require("./default_speech");
const app = new App();
app.use(new Alexa(), new GoogleAssistant(), new JovoDebugger(), new FileDb());
let sp = "";
async EmailViewsByContactIntent() {
try {
const viewEmailId =
this.$session.$data.viewEmailIdSessionKey != null
? this.$session.$data.viewEmailIdSessionKey
: this.$inputs.view_email_Id_Number.value;
let pageIndex =
this.$session.$data.viewEmailPageIndex != null
? this.$session.$data.viewEmailPageIndex
: 1;
const result = await custom.email_views_by_emailId(
viewEmailId,
pageIndex
);
const records = result.data.records;
if (records.length > 0) {
const totalRecords = result.data.paging.totalRecords;
this.$session.$data.viewEmailTotalPages = totalRecords;
sp = `i have found a total of ${totalRecords} following view records. `;
if (totalRecords > 5) {
sp += `i will tell you 5 records at a time. for next 5 records, please say, next. `;
this.$session.$data.viewEmailIdSessionKey = this.$inputs.view_email_Id_Number.value;
this.$session.$data.viewEmailPageIndex++;
}
for (let i = 0; i < records.length; i++) {
const r = records[i];
/* Here I want to pass r.contactID as contactId in the function contact_detail like this: */
const contact = await custom.contact_detail(r.contactID);
const contact_name = contact.data.firstName + " " + contact.data.lastName;
/* The above two lines of code fetch contact_name for the first r.contactID and for the rest I get an empty string only. */
const formatted_date = r.date.split(" ")[0];
sp += `contact ID ${spellOut_speech_builder(
r.contactID
)} had viewed on ${formatted_date} from IP address ${
r.ipAddress
}. name of contact is, ${contact_name}. `;
}
if (totalRecords > 5) {
sp += ` please say, next, for next 5 records. `;
}
} else {
sp = ``;
}
this.ask(sp);
} catch (e) {
this.tell(e);
}
}
I am building an alexa skill using JOVO framework and nodeJS.
UPDATE #2
As a test, I only returned the contactId which I am passing to the contact_detail function and I am getting the correct value back to the above code under my first UPDATE.
async contact_detail: contactId => {
return contactId;
}
It seems even after getting the value right, the function is somehow failing to execute. However, the same contact_detail function works perfectly OK, when I am calling it from another place. Only doesn't not work inside a loop.
What could be the reason?
I must be missing something but don't know what!
You are mixing async await and promises together which is causing you confusion. You typically would use one of the other(as async await effectivly provides syntax sugar so you can avoid dealing with the verbose promise code) in a given location.
Because you mixed the two you are in a weird area where the behavior is harder to nail down.
If you want to use async await your functions should look like
async contact_detail: contactId => {
try {
const body = await rp({
url: 'myapiurl2',
qs: { ... }
});
return JSON.parse(body);
} catch(e) {
console.log(e);
//This will return undefined in exception cases. You may want to catch at a higher level.
}
};
or with promises
async contact_detail: contactId => {
return rp({
url: 'myapiurl2',
qs: { ... }
})
.then( body => JSON.parse(body))
.catch( error => {
console.log(error);
//This will return undefined in exception cases. You probably dont want to catch here.
});
};
Keep in mind your current code executing the function will do each call in series. If you want to do them in parallel you will need to call the function a bit differently and use something like Promise.all to resolve the result.
Here you go:
...
const result = await email_views(99999); // function#1
const records = result.data.records;
...
let names = "";
await Promise.all(records.map(async record => {
let cId = record.contactID;
let contact = await contact_detail(cId);
names += contact.data.firstName + " " + contact.data.lastName + " ";
});
console.log(names);
...
I'm posting this as an answer only because I need to show you some multi-line code as part of throubleshooting this. Not sure this solves your issue yet, but it is a problem.
Your contact_detail() function is not properly returning errors. Instead, it eats the error and resolves with an empty object. That could be what is causing your blank names. It should just return the promise directly and if you want to log the error, then it needs to rethrow. Also, there's no reason for it to be declared async or to use await. You can just return the promise directly. You can also let request-promise parts the JSON response for you too.
Also, I notice, there appears to be a syntax error in your .catch() which could also be part of the problem.
contact_detail: contactId => {
return rp({
url: 'myapiurl2',
qs: { accessToken: 'xyz', contactID: contactId },
json: true,
method: 'GET'
}).catch( error => {
// log error and rethrow so any error propagates
console.log(error);
throw error;
});
};
Then, you would call this like you originally were (note you still use await when calling it because it returns a promise):
...
const result = await email_views(99999); // function#1
const records = result.data.records;
...
let names = "";
for( let i=0; i<records.length; i++) {
...
const cId = records[i].contactID;
const contact = await contact_detail(cId);
names += contact.data.firstName + " " + contact.data.lastName + " ";
...
}
console.log(names);
...