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Node.js MongoDB Find


In MongoDB we use the find and findOne methods to find data in a collection.

Just like the SELECT statement is used to find data in a table in a MySQL database.

Find One

To select data from a collection in MongoDB, we can use the findOne() method.

The findOne() method returns the first occurrence in the selection.

The first parameter of the findOne() method is a query object. In this example we use an empty query object, which selects all documents in a collection (but returns only the first document).

Example

Find the first document in the customers collection:

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

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  db.collection("customers").findOne({}, function(err, result) {
    if (err) throw err;
    console.log(result.name);
    db.close();
  });
});
Run example »

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

Run "demo_mongodb_findone.js"

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

Which will give you this result:

Company Inc.


Find All

To select data from a table in MongoDB, we can also use the find() method.

The find() method returns all occurrences in the selection.

The first parameter of the find() method is a query object. In this example we use an empty query object, which selects all documents in the collection.

No parameters in the find() method gives you the same result as SELECT * in MySQL.

Example

Find all documents in the customers collection:

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

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  db.collection("customers").find({}).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
  });
});
Run example »

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

Run "demo_mongodb_find.js"

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

Which will give you this result:

[
  { _id: 58fdbf5c0ef8a50b4cdd9a84 , name: 'John', address: 'Highway 71'},
  { _id: 58fdbf5c0ef8a50b4cdd9a85 , name: 'Peter', address: 'Lowstreet 4'},
  { _id: 58fdbf5c0ef8a50b4cdd9a86 , name: 'Amy', address: 'Apple st 652'},
  { _id: 58fdbf5c0ef8a50b4cdd9a87 , name: 'Hannah', address: 'Mountain 21'},
  { _id: 58fdbf5c0ef8a50b4cdd9a88 , name: 'Michael', address: 'Valley 345'},
  { _id: 58fdbf5c0ef8a50b4cdd9a89 , name: 'Sandy', address: 'Ocean blvd 2'},
  { _id: 58fdbf5c0ef8a50b4cdd9a8a , name: 'Betty', address: 'Green Grass 1'},
  { _id: 58fdbf5c0ef8a50b4cdd9a8b , name: 'Richard', address: 'Sky st 331'},
  { _id: 58fdbf5c0ef8a50b4cdd9a8c , name: 'Susan', address: 'One way 98'},
  { _id: 58fdbf5c0ef8a50b4cdd9a8d , name: 'Vicky', address: 'Yellow Garden 2'},
  { _id: 58fdbf5c0ef8a50b4cdd9a8e , name: 'Ben', address: 'Park Lane 38'},
  { _id: 58fdbf5c0ef8a50b4cdd9a8f , name: 'William', address: 'Central st 954'},
  { _id: 58fdbf5c0ef8a50b4cdd9a90 , name: 'Chuck', address: 'Main Road 989'},
  { _id: 58fdbf5c0ef8a50b4cdd9a91 , name: 'Viola', address: 'Sideway 1633'}
]

Find Some

The second parameter of the find() method is an object describing which fields to include in the result.

This parameter is optional, and if omitted, all fields will be included in the result.

Example

Return the fields "name" and "address" of all documents in the customers collection:

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

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  db.collection("customers").find({}, { _id: false, name: true, address: true }).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
  });
});
Run example »

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

Run "demo_mongodb_find_fields.js"

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

Which will give you this result:

[
  { name: 'John', address: 'Highway 71'},
  { name: 'Peter', address: 'Lowstreet 4'},
  { name: 'Amy', address: 'Apple st 652'},
  { name: 'Hannah', address: 'Mountain 21'},
  { name: 'Michael', address: 'Valley 345'},
  { name: 'Sandy', address: 'Ocean blvd 2'},
  { name: 'Betty', address: 'Green Grass 1'},
  { name: 'Richard', address: 'Sky st 331'},
  { name: 'Susan', address: 'One way 98'},
  { name: 'Vicky', address: 'Yellow Garden 2'},
  { name: 'Ben', address: 'Park Lane 38'},
  { name: 'William', address: 'Central st 954'},
  { name: 'Chuck', address: 'Main Road 989'},
  {  name: 'Viola', address: 'Sideway 1633'}
]

By default, all fields are included in the result, and you only have to specify the fields you do not want to be included in the result:

Example

This example will give you the same result as the example above:

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

MongoClient.connect(url, function(err, db) {
  if (err) throw err;
  db.collection("customers").find({}, { _id: false }).toArray(function(err, result) {
    if (err) throw err;
    console.log(result);
    db.close();
  });
});
Run example »

The Result Object

As you can see from the result of the example above, the result can be converted into an array containing each document as an object.

To return e.g. the address of the third document, just refer to the third array object's address property:

Example

Return the address of the third document:

console.log(result[2].address);

Which will produce this result:

Apple st 652