An important step in the process of Development is connecting with the database. This has been made easy with mongoose
, which is an npm dependency.
After you have initialized your express app, install mongoose using the following npm command :
npm install mongoose
Mongoose can be used in 3 simple steps :
Setting up a port
Since mongoDB
runs on a server, we need to run a mongoDB server locally. If you have mongoDB installed locally, just head to your preferred terminal and run :
mongod
Your mongoDB server is up and running on port: 27017
Importing Mongoose
You can import and use mongoose in 2 places :
In the server.js
file
You can import and use mongoose in the main server file itself :
javascript
const mongoose = require("mongoose");
In a Separate Database Folder
You can also implement the modular approach where you can create a separate db
folder and setup connection inside it in a connections.js
file.
Connecting To Server
The final step is to initialize and setup the mongoDB connection.
The process is to initialize the mongoose connection and listen for the result returned.
javascript
const mongoose = require("mongoose");
mongoose
.connect(process.env.DB_URL, {
useNewUrlParser: true,
useFindAndModify: false,
useUnifiedTopology: true
})
.then((result) => {
console.log("Database connected at port : "+process.env.DB_URL);
})
.catch((err) => {
console.log(err);
});
Now the question is what are these terms :
javascript
useNewUrlParser: true,
useFindAndModify: false,
useUnifiedTopology: true
These are optional arguments being passed to the connection method.
1. useNewUrlParser
The underlying MongoDB driver has deprecated their current connection string parser. Because this is a major change, they added the useNewUrlParser flag to allow users to fall back to the old parser if they find a bug in the new parser. You should set
javascript
useNewUrlParser: true
unless that prevents you from connecting.
2. useFindAndModify
true
by default. Set to false to make findOneAndUpdate() and findOneAndRemove() use native findOneAndUpdate() rather than findAndModify().
findOneAndUpdate
allows for just updates - no deletes or replaces etc.
findAndModify
can do a lot more including replace, delete and so on.
3. useUnifiedTopology
false
by default. Set to true to use the MongoDB driver's new connection management engine. This option should always be set to true, except for the unlikely case that it prevents you from maintaining a stable connection.
There we go! We have successfully setup a mongoDB connection.
Happy Hacking!!
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