Python Mongodb – Delete_one()

Mongodb is a very popular cross platform document-oriented, NoSQL(stands for “not only SQL”) database program, written in C++. It stores data in JSON format(as key-values pairs), which makes it easy to use. Mongdb can run over multiple servers, balancing the load to keep the system up and run in case of hardware failure.

Connecting to a Database

Step 1 – Establishing Connection: Port number Default: 27017

conn = MongoClient(‘localhost’, port-number)

If using default port-number i.e. 27017. Alternate connection method:

conn = MongoClient()

Step 2 – Create Database or Switch to Existing Database:

db = conn.dabasename

Create a collection or Switch to existing collection:

collection = db.collection_name

Deleting document from Collection or Database

In MongoDB, a single document can be deleted by the method delete_one(). The first parameter of the method would be a query object which defines the document to be deleted. If there is a reoccurrence of the same document, only the first appeared document would be deleted.

Note: Deleting a document is same as deleting a record in the case of SQL.

Consider the sample databse:

'_id': 2.0, 'Name': 'Golu', 'Class': '3'}
{'_id': 3.0, 'Name': 'Raja', 'Class': '4'}
{'_id': 4.0, 'Name': 'Moni', 'Class': '5'}