Step-by-Step Guide to Create a Database in MongoDB

MongoDB is a popular NoSQL database known for its flexibility and scalability. Unlike traditional relational databases, MongoDB uses a document-based model and collections, making it ideal for modern applications. This blog provides a step-by-step guide to creating a database in MongoDB.

Table of Contents

Step 1: Install MongoDB

Before you start, ensure MongoDB is installed on your system.

Download MongoDB:
- Visit MongoDB’s official website.
- Choose the appropriate version for your operating system and install it.
Start the MongoDB Server:
- Open your terminal or command prompt.
- Run the command: mongod
- This will start the MongoDB server on your local machine.

Step 2: Open the MongoDB Shell

Once the server is running, open the MongoDB shell to interact with the database.

Open a new terminal window or command prompt.
Enter: mongo
- This connects you to the running MongoDB server.

Step 3: Create a Database

In MongoDB, databases are created dynamically when data is inserted. However, you can specify a database explicitly to start working with it.

Switch to a New or Existing Database:
- Use the use command: use myDatabase
- Replace myDatabase with your desired database name.
- If the database doesn’t exist, MongoDB will create it once you insert data into it.
Verify the Database:
- After switching to the database, you can check the current database by typing: db
- This will display the name of the active database.

Step 4: Create a Collection

Collections in MongoDB are equivalent to tables in relational databases. To create a collection, insert data into it.

Insert Data into a Collection:
- Use the insertOne method: db.myCollection.insertOne({ name: "John Doe", age: 30, city: "New York" })
- Replace myCollection with your collection name.
- This command creates a new collection (myCollection) if it doesn’t exist and adds the provided document.
Verify the Collection:
- To check all collections in the database, run: show collections

Step 5: Insert and Query Data

Now that your database and collection are set up, you can insert and retrieve data.

Insert Multiple Documents: db.myCollection.insertMany([ { name: "Jane Doe", age: 25, city: "Los Angeles" }, { name: "Mike Smith", age: 35, city: "Chicago" } ])
Query the Data:
- Retrieve all documents: db.myCollection.find()
- Retrieve documents with specific criteria: db.myCollection.find({ city: "New York" })

Step 6: Confirm the Database Creation

MongoDB doesn’t permanently create a database until data is added. After inserting data, confirm the database creation:

List All Databases:
- Run: show dbs
- Your database (myDatabase) should now appear in the list.

Step 7: Optional – Delete the Database

If you no longer need the database, you can delete it.

Switch to the Database: use myDatabase
Drop the Database: db.dropDatabase()
- This removes the database and all its collections permanently.