sqlite3_python_tutorial.md

SQLite3 is a C library that provides a lightweight disk-based database that doesn’t require a separate server process and allows accessing the database using a nonstandard variant of the SQL query language. In this tutorial, we will learn how to use SQLite3 with Python.

Before we start, make sure you have the sqlite3 library installed in your Python environment.

Importing the library

import sqlite3

Connecting to a database To connect to a database in SQLite, you need to create a Connection object, which represents the database. If the database does not exist, SQLite will create it for you.

conn = sqlite3.connect("example.db")

Creating a cursor object A cursor is used to traverse the records from the result set. A cursor object is created by calling the cursor method of the Connection object.

cursor = conn.cursor()

Creating a table

cursor.execute("CREATE TABLE IF NOT EXISTS employees (id INT PRIMARY KEY, name TEXT, salary REAL)")

Inserting data into a table

cursor.execute("INSERT INTO employees VALUES (1, 'John Doe', 5000)")
cursor.execute("INSERT INTO employees VALUES (2, 'Jane Doe', 6000)")
conn.commit()

Querying data from a table

cursor.execute("SELECT * FROM employees")
employees = cursor.fetchall()
for employee in employees:
    print(employee)

Updating data in a table

cursor.execute("UPDATE employees SET salary = 7000 WHERE id = 2")
conn.commit()

Deleting data from a table

cursor.execute("DELETE FROM employees WHERE id = 1")
conn.commit()

Closing the connection

conn.close()

This is a basic tutorial on how to use SQLite3 with Python. With the knowledge of SQL and Python, you can now create more complex applications that interact with databases.