Mongodb integration
Syntax#
- db.collection.insertOne(document, options(w, wtimeout, j, serializeFuntions, forceServerObjectId, bypassDocumentValidation), callback)
- db.collection.insertMany([documents], options(w, wtimeout, j, serializeFuntions, forceServerObjectId, bypassDocumentValidation), callback)
- db.collection.find(query)
- db.collection.updateOne(filter, update, options(upsert, w, wtimeout, j, bypassDocumentValidation), callback)
- db.collection.updateMany(filter, update, options(upsert, w, wtimeout, j), callback)
- db.collection.deleteOne(filter, options(upsert, w, wtimeout, j), callback)
- db.collection.deleteMany(filter, options(upsert, w, wtimeout, j), callback)
Parameters#
| Parameter | Details |
|---|---|
| document | A javascript object representing a document |
| documents | An array of documents |
| query | An object defining a search query |
| filter | An object defining a search query |
| callback | Function to be called when the operation is done |
| options | (optional) Optional settings (default: null) |
| w | (optional) The write concern |
| wtimeout | (optional) The write concern timeout. (default: null) |
| j | (optional) Specify a journal write concern (default: false) |
| upsert | (optional) Update operation (default: false) |
| multi | (optional) Update one/all documents (default: false) |
| serializeFunctions | (optional) Serialize functions on any object (default: false) |
| forceServerObjectId | (optional) Force server to assign _id values instead of driver (default: false) |
| bypassDocumentValidation | (optional) Allow driver to bypass schema validation in MongoDB 3.2 or higher (default: false) |
| ## Connect to MongoDB | |
| Connect to MongoDB, print ‘Connected!’ and close the connection. |
const MongoClient = require('mongodb').MongoClient;
var url = 'mongodb://localhost:27017/test';
MongoClient.connect(url, function(err, db) { // MongoClient method 'connect'
if (err) throw new Error(err);
console.log("Connected!");
db.close(); // Don't forget to close the connection when you are done
});MongoClient method Connect()
MongoClient.connect(url, options, callback)
| Argument | Type | Description |
|---|---|---|
url |
string | A string specifying the server ip/hostname, port and database |
options |
object | (optional) Optional settings (default: null) |
callback |
Function | Function to be called when the connection attempt is done |
The callback function takes two arguments
err: Error - If an error occurs theerrargument will be defineddb: object - The MongoDB instance
Insert a document
Insert a document called ‘myFirstDocument’ and set 2 properties, greetings and farewell
const MongoClient = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017/test';
MongoClient.connect(url, function (err, db) {
if (err) throw new Error(err);
db.collection('myCollection').insertOne({ // Insert method 'insertOne'
"myFirstDocument": {
"greetings": "Hellu",
"farewell": "Bye"
}
}, function (err, result) {
if (err) throw new Error(err);
console.log("Inserted a document into the myCollection collection!");
db.close(); // Don't forget to close the connection when you are done
});
});Collection method insertOne()
db.collection(collection).insertOne(document, options, callback)
| Argument | Type | Description |
|---|---|---|
collection |
string | A string specifying the collection |
document |
object | The document to be inserted into the collection |
options |
object | (optional) Optional settings (default: null) |
callback |
Function | Function to be called when the insert operation is done |
The callback function takes two arguments
err: Error - If an error occurs theerrargument will be definedresult: object - An object containing details about the insert operation
Read a collection
Get all documents in the collection ‘myCollection’ and print them to the console.
const MongoClient = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017/test';
MongoClient.connect(url, function (err, db) {
if (err) throw new Error(err);
var cursor = db.collection('myCollection').find(); // Read method 'find'
cursor.each(function (err, doc) {
if (err) throw new Error(err);
if (doc != null) {
console.log(doc); // Print all documents
} else {
db.close(); // Don't forget to close the connection when you are done
}
});
});Collection method find()
db.collection(collection).find()
| Argument | Type | Description |
|---|---|---|
collection |
string | A string specifying the collection |
Update a document
Find a document with the property { greetings: 'Hellu' } and change it to { greetings: 'Whut?' }
const MongoClient = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017/test';
MongoClient.connect(url, function (err, db) {
if (err) throw new Error(err);
db.collection('myCollection').updateOne({ // Update method 'updateOne'
greetings: "Hellu" },
{ $set: { greetings: "Whut?" }},
function (err, result) {
if (err) throw new Error(err);
db.close(); // Don't forget to close the connection when you are done
});
});Collection method updateOne()
db.collection(collection).updateOne(filter, update, options. callback)
| Parameter | Type | Description |
|---|---|---|
filter |
object | Specifies the selection critera |
update |
object | Specifies the modifications to apply |
options |
object | (optional) Optional settings (default: null) |
callback |
Function | Function to be called when the operation is done |
The callback function takes two arguments
err: Error - If an error occurs the err argument will be defineddb: object - The MongoDB instance
Delete a document
Delete a document with the property { greetings: 'Whut?' }
const MongoClient = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017/test';
MongoClient.connect(url, function (err, db) {
if (err) throw new Error(err);
db.collection('myCollection').deleteOne(// Delete method 'deleteOne'
{ greetings: "Whut?" },
function (err, result) {
if (err) throw new Error(err);
db.close(); // Don't forget to close the connection when you are done
});
});Collection method deleteOne()
db.collection(collection).deleteOne(filter, options, callback)
| Parameter | Type | Description |
|---|---|---|
filter |
object | A document specifying the selection critera |
options |
object | (optional) Optional settings (default: null) |
callback |
Function | Function to be called when the operation is done |
The callback function takes two arguments
err: Error - If an error occurs the err argument will be defineddb: object - The MongoDB instance
Delete multiple documents
Delete ALL documents with a ‘farewell’ property set to ‘okay’.
const MongoClient = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017/test';
MongoClient.connect(url, function (err, db) {
if (err) throw new Error(err);
db.collection('myCollection').deleteMany(// MongoDB delete method 'deleteMany'
{ farewell: "okay" }, // Delete ALL documents with the property 'farewell: okay'
function (err, result) {
if (err) throw new Error(err);
db.close(); // Don't forget to close the connection when you are done
});
});Collection method deleteMany()
db.collection(collection).deleteMany(filter, options, callback)
| Parameter | Type | Description |
|---|---|---|
filter |
document | A document specifying the selection critera |
options |
object | (optional) Optional settings (default: null) |
callback |
function | Function to be called when the operation is done |
The callback function takes two arguments
err: Error - If an error occurs the err argument will be defineddb: object - The MongoDB instance
Simple connect
MongoDB.connect('mongodb://localhost:27017/databaseName', function(error, database) {
if(error) return console.log(error);
const collection = database.collection('collectionName');
collection.insert({key: 'value'}, function(error, result) {
console.log(error, result);
});
});Simple connect, using promises
const MongoDB = require('mongodb');
MongoDB.connect('mongodb://localhost:27017/databaseName')
.then(function(database) {
const collection = database.collection('collectionName');
return collection.insert({key: 'value'});
})
.then(function(result) {
console.log(result);
});
```