How to use database in Python?

With the passage of time, data has always been considered the cornerstone of enterprise survival, and the use of databases has become more and more popular in a wide range of fields. As a Python developer, it is very important to master how to use databases in Python. In this article, we will discuss how to use a database in Python and why you need to use a database.

Why do you need to use a database?

Before discussing how to use a database in Python, let us first understand why we need to use a database. Here are some reasons to use a database:

1. Data Storage: In many applications, storing data in files can be cumbersome, so it is easier to use a database to store the data.
2. Data query: Querying data in large data sets is easier and faster than looking for data in files.
3. Data update: Updating data can be cumbersome when it is stored in files, but using a database makes it easy to update data.
4. Data backup and recovery: The database provides a mechanism to back up and restore data, which can protect data in the event of hardware failure or other catastrophic events.

How to use database in Python?

There are many libraries in Python for operating databases. Below we will discuss using two of the most popular and widely used databases in Python: MySQL and PostgreSQL.

1. MySQL

MySQL is a free and open source relational database management system commonly used in web application development and client/server architectures. The following are the steps to connect to MySQL using Python:

• step 1: Install the mysql-connector-python library, use the following command:

  pip install mysql-connector -python

• step 2: Import mysql.connector library:

  import mysql.connector

• step 3: Establish a connection with the MySQL server:

mydb = mysql.connector.connect(
  host="localhost",
  user="yourusername",
  password="yourpassword"
)

• step 4: Create a MySQL database:

mycursor = mydb.cursor()
mycursor.execute("CREATE DATABASE mydatabase")

• step 5: Check whether the database exists, using the following line of code:

mycursor.execute("SHOW DATABASES")
for x in mycursor:
  print(x)

2. PostgreSQL

PostgreSQL is a free and open source object-relational database management system for web applications, mobile Frequently used in applications and client/server architectures. The following are the steps to connect to PostgreSQL using Python:

• step 1: Install the psycopg2 library, use the following command:

  pip install psycopg2

• step 2: Import psycopg2 library:

  import psycopg2

• step 3: Establish a connection with the PostgreSQL server:

mydb = psycopg2.connect(
  host="localhost",
  database="mydatabase",
  user="myusername",
  password="mypassword"
)

• #step 4: Create a PostgreSQL table:

mycursor = mydb.cursor()
mycursor.execute("CREATE TABLE customers (name VARCHAR(255), address VARCHAR(255))")

• step 5: Insert data into the table:

mycursor = mydb.cursor()
sql = "INSERT INTO customers (name, address) VALUES (%s, %s)"
val = ("John", "Highway 21")
mycursor.execute(sql, val)
mydb.commit()

Summary

In this article, we discussed why you need to use a database and how to use two of the most popular databases in Python: MySQL and PostgreSQL. There are many other database libraries in Python's huge ecosystem, so you should choose the one that suits your needs. After mastering the basic knowledge, you can use Python to operate the database for data storage, query and update.

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