DEV Community

Cover image for MongoDB: Inserting Data - Series #08
Functional Javascript
Functional Javascript

Posted on

MongoDB: Inserting Data - Series #08


In the last article in the series I showed how to establish a connection to MongoDB.

Here I'll show how to interact with data using that connection object.

Here's a simple insert:

insert a single doc into a coll

@param {string} dbName
@param {string} collName
@param {object} o - the doc to insert into the coll
@return {Promise<object> | null} the inserted doc, or null if exception
const mgInsertOne = async (dbName, collName, o) => {
  const client = await mongoAsync();
  try {
    return await client.db(dbName).collection(collName).insertOne({ ts: getDateStandardWithSeconds(), ...o });
  } catch (err) {
    return null;
  } finally {
    if (client) {

export default mgInsertOne;
Enter fullscreen mode Exit fullscreen mode

Here's an example usage:

 mgInsertOne("myCompanyDB", "userColl", { firstName: "fluffy" });
Enter fullscreen mode Exit fullscreen mode

Here's the sample output:

  ts: '[2021-02-09 Tue 09:21:21]',
  firstName: 'fluffy',
  _id: 6022c491834ad44058181f5b
Enter fullscreen mode Exit fullscreen mode


The "mgInsertOne" utility func will return our inserted record. This is useful for delivering feedback in the UI.

Notice the utility func closes the client connection in the "finally" block

If the DB does not exists, it gets created dynamically.

If the collection does not exists, it gets created dynamically.

If you don't supply a primary key, which is field called, "_id", then the framework autogenerates one for you.

The client code of this func is a simple one liner. Wrap it in an Express.js route, push it to a provider like Heroku, and you're live within minutes — from composing the query — to having it available for clients to use.

What's Next?

If you have any questions let me know.

The best way to perform queries in Mongo is using their "aggregate" func. It takes an arr of objs. Each obj is a part of the query that we're composing. It's an extremely powerful command that allows to you to shape and reshape your data any way your wish.
We'll cover more real-life examples of this powerful tool.
Start reading from the beginning of this series to get an introduction to this "Aggregation Framework".

Discussion (0)