Programming Essentials Python - CRUD Operations - Function Get Database Connection

Description: This article focuses on automating database connections using Python. It provides step-by-step instructions on creating a function to get a database connection and how to reuse this function for performing CRUD operations on various databases. The visual aid for this article is a YouTube video that demonstrates the process in action.

Explanation for the video:

[YouTube Video Placeholder]

Key Concepts Explanation

Key Concept 1

In this concept, we develop a function called get_connection that takes essential parameters to establish a connection to the database and returns the connection object. Here is the code snippet:

import psycopg2

def get_connection(host, port, database, user, password):
    connection = None
    try:
        connection = psycopg2.connect(
            host=host,
            port=port,
            database=database,
            user=user,
            password=password
        )
    except Exception as e:
        raise(e)
    return connection

Key Concept 2

Another key concept involves creating specific connection objects like sms_connection and retail_connection for hypothetical databases - sms and retail. Here are the code snippets for establishing these connections:

host = 'pg.itversity.com'
port = '5432'
database = 'sms_db'
user = 'sms_user'
password = 'itversity'

sms_connection = get_connection(
    host=host,
    port=port,
    database=database,
    user=user,
    password=password
)
host = 'pg.itversity.com'
port = '5432'
database = 'retail_db'
user = 'retail_user'
password = 'itversity'

retail_connection = get_connection(
    host=host,
    port=port,
    database=database,
    user=user,
    password=password
)

Hands-On Tasks

Here are some hands-on tasks you can perform to solidify your understanding:

  1. Create a function to establish database connections for different databases.
  2. Invoke the function with appropriate parameters to create connection objects.

Conclusion

In conclusion, this article has walked you through automating database connections using Python. By creating a reusable function, you can simplify the process of connecting to databases and performing operations. Practice these concepts and feel free to engage with the community for further learning.

Function - Get Database Connection

Let’s develop a function to get a database connection for reuse in subsequent tasks such as performing CRUD operations.

  • The get_connection function establishes a connection to the database using the provided parameters and returns the connection object.

  • Connection objects like sms_connection and retail_connection are created for hypothetical databases - sms and retail.

  • The functions and connection objects can be reused in other notebooks by utilizing %run.

  • Ensure to replace the placeholders for host, port, database, user, and password with your actual database credentials.

import psycopg2

def get_connection(host, port, database, user, password):
    connection = None
    try:
        connection = psycopg2.connect(
            host=host,
            port=port,
            database=database,
            user=user,
            password=password
        )
    except Exception as e:
        raise(e)
    return connection

Feel free to customize the function and connection objects according to your database setup.

Watch the video tutorial here