Create MongoDB Database - PyMongo - Examples

Create a Database using PyMongo

To create a Database in MongoDB from Python using PyMongo, follow these steps:

  1. Create a client to the MongoDB instance.
  2. Provide the name of the database to the client. It returns a reference to the database.
  3. Now you can use this database reference to modify your collections or documents.

Examples

1. Create MongoDB Database Named "organisation"

In the following program, we create a database named organisation.

Python Program

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")

# Use database named "organisation"
mydb = myclient["organisation"]

Explanation:

  1. We first import the pymongo library.
  2. We create a MongoDB client object myclient to connect to the local MongoDB instance.
  3. We reference the database organisation by providing its name to the myclient object. This does not create the database yet.
  4. Database creation happens only once we insert at least one document into it, which we will demonstrate next.

Note: A database is created in MongoDB only after there is content (such as a document) inserted into it. To see the database in the list of databases, we need to insert a document.

2. Create a Database and Insert a Document

In this example, we will create a database, insert a document into it, and then list the available databases to confirm the creation.

Python Program

import pymongo

myclient = pymongo.MongoClient("mongodb://localhost:27017/")

# Use database named "organisation"
mydb = myclient["organisation"]

# Use collection named "developers"
mycol = mydb["developers"]

# A document
developer = { "name": "Lini", "address": "Sweden" }

# Insert a document to the collection
x = mycol.insert_one(developer)

# List the databases
for db in myclient.list_databases():
    print(db)

Explanation:

  1. After referencing the organisation database, we create a collection named developers within it.
  2. We create a sample document developer with fields for name and address.
  3. The document is inserted into the collection using insert_one() method. This action triggers the creation of the database in MongoDB.
  4. Finally, we use the list_databases() method to list all databases and confirm that organisation now exists.

Output:

3. Create and List a Database in Remote MongoDB Instance

In this example, we will connect to a remote MongoDB instance, create a database, and list it.

Python Program

import pymongo

myclient = pymongo.MongoClient("mongodb://remote_host:27017/")

# Use database named "company"
mydb = myclient["company"]

# Use collection named "employees"
mycol = mydb["employees"]

# A document
employee = { "name": "Alice", "position": "Engineer" }

# Insert a document
x = mycol.insert_one(employee)

# List the databases
for db in myclient.list_databases():
    print(db)

Explanation:

  1. This program is similar to the previous one, but it connects to a remote MongoDB instance instead of the local one.
  2. We connect to the MongoDB server running on a remote host remote_host at port 27017.
  3. We proceed with the same steps to create the company database, insert an employee document, and list the databases.

Output:

Summary

In this PyMongo Tutorial, we learned how to create a MongoDB database, with examples showing how to:

  • Create a database with a given name.
  • Insert a document into a database to trigger its creation.
  • Connect to a remote MongoDB instance.
  • List all databases to verify creation.

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