Insert

To insert a record, or document as it is called in MongoDB, into a collection, we use the insertOne() method.

A document in MongoDB is the same as a record in MySQL.

The first parameter of the insertOne() method is an object containing the name(s) and value(s) of each field in the document you want to insert.

It also takes a callback function where you can work with any errors, or the result of the insertion.

Example

To insert a document in the "customers" collection, use the following code:

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/";

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  var dbo = db.db("mydb");
  var myobj = { name: "Company Inc", address: "Highway 37" };
  dbo.collection("customers").insertOne(myobj, function(err, res) {
    if (err) throw err;
    console.log("1 document inserted");
    db.close();
  });
});

Save the code above in a file called demo_mongodb_insert.js and run the file:

Run "demo_mongodb_insert.js"

C:\Users\Your Name>node demo_mongodb_insert.js

This will give you the following result:

1 document inserted

Note

If you try to insert documents into a collection that does not exist, MongoDB will create the collection automatically.

Insert Multiple Documents

To insert multiple documents into a collection in MongoDB, we use the insertMany() method.

The first parameter of the insertMany() method is an array of objects containing the data you want to insert.

It also takes a callback function where you can work with any errors, or the result of the insertion.

Example

To insert multiple documents in the "customers" collection, use the following code:

// Same setup as previous example

var myobj = [
  { name: 'John', address: 'Highway 71'},
  // Additional documents...
];

dbo.collection("customers").insertMany(myobj, function(err, res) {
  if (err) throw err;
  console.log("Number of documents inserted: " + res.insertedCount);
  db.close();
});

Save the code above in a file called demo_mongodb_insert_multiple.js and run the file.

This will give you the result:

Number of documents inserted: 14

The Result Object

When executing the insertMany() method, a result object is returned.

The result object contains information about how the insertion affected the database.

The object returned from the example above looks like this:

{
  result: { ok: 1, n: 14 },
  // Additional properties...
}

The values of the properties can be displayed like this:

console.log(res.insertedCount);

Which will produce this result:

14

Info

If you do not specify an _id field, then MongoDB will add one for you and assign a unique id for each document.

In the example above, no _id field was specified, and MongoDB assigned a unique _id for each document.

If you do specify the _id field, the value must be unique for each document.