Flask and MySQL are two powerful tools that can be combined to create a robust and secure login page for your web application. As a web developer, I have had the opportunity to work with these technologies extensively and I must say, the possibilities are truly endless. In this article, I will guide you through the process of creating a login page using Flask and MySQL, while also sharing some personal insights and tips along the way.
Why Flask and MySQL?
Before diving into the technical details, let’s talk about why Flask and MySQL are a great choice for building a login page. Flask is a micro web framework written in Python, which makes it incredibly easy to get started with web development. It provides a simple yet powerful set of tools and libraries that allow you to create web applications quickly and efficiently.
On the other hand, MySQL is a popular open-source relational database management system that provides excellent performance and scalability. It allows you to store and retrieve data efficiently, making it an ideal choice for handling user authentication and login information.
Combining Flask and MySQL gives us the best of both worlds: a simple and flexible web framework coupled with a robust and reliable database system. Now, let’s jump into the technical details!
Setting Up Flask and MySQL
Before we can start building our login page, we need to set up Flask and MySQL on our development environment. First, we’ll need to install Flask by running the following command:
pip install flask
Next, we’ll need to install the Flask-MySQL extension, which provides the necessary tools to connect Flask with a MySQL database. We can install it using pip:
pip install flask-mysql
Once the installation is complete, we can import Flask and Flask-MySQL in our Python script to start building our login page.
Creating the Login Page
Now that we have our development environment set up, we can start creating our login page. The first step is to create a new Flask route that handles the login functionality. Let’s call it /login:
@app.route('/login', methods=['GET', 'POST'])
The above code creates a new route that listens for both GET and POST requests to /login. This allows us to display the login form to the user and process the submitted login credentials.
Inside the route function, we can check the request method to determine whether the user is submitting the login form or simply accessing the login page. If the method is GET, we can render the login form template using Flask’s template engine:
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'GET':
return render_template('login.html')
The above code uses the render_template function to render the login.html template, which contains the HTML code for our login form.
Now, let’s take a closer look at the login form itself. The form should include two input fields: one for the username and another for the password. It should also have a submit button that triggers the form submission:
<form action="/login" method="POST">
<label for="username">Username:</label>
<input type="text" id="username" name="username"><br>
<label for="password">Password:</label>
<input type="password" id="password" name="password"><br>
<input type="submit" value="Login">
</form>
The form above defines an action of /login and a method of POST, which means that when the user submits the form, the data will be sent to the same /login route using the POST method.
Back to our Flask route, when the user submits the login form, the request method will be POST. We can retrieve the submitted username and password from the request form data and compare them with the credentials stored in our MySQL database:
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'GET':
return render_template('login.html')
elif request.method == 'POST':
username = request.form['username']
password = request.form['password']
# Verify credentials against MySQL database
At this point, we need to establish a connection to our MySQL database and execute a SQL query to retrieve the user’s credentials. Flask-MySQL provides a convenient way to connect to a MySQL database using the MySQL class. We can instantiate this class and configure it with the necessary credentials:
from flaskext.mysql import MySQL
app = Flask(__name__)
mysql = MySQL()
app.config['MYSQL_DATABASE_USER'] = 'username'
app.config['MYSQL_DATABASE_PASSWORD'] = 'password'
app.config['MYSQL_DATABASE_DB'] = 'database'
app.config['MYSQL_DATABASE_HOST'] = 'localhost'
mysql.init_app(app)
The above code sets up the MySQL connection using the Flask-MySQL extension. Replace the placeholders with your MySQL credentials.
Now, we can execute a SQL query to retrieve the user’s credentials from the database:
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'GET':
return render_template('login.html')
elif request.method == 'POST':
username = request.form['username']
password = request.form['password']
conn = mysql.connect()
cursor = conn.cursor()
cursor.execute("SELECT * FROM users WHERE username = %s AND password = %s", (username, password))
result = cursor.fetchone()
conn.close()
if result:
# User authentication successful
else:
# Invalid credentials
The above code executes a SQL query that selects all rows from the users table where the username and password match the submitted values. The fetchone() method retrieves the first row, or None if no match is found.
Finally, we can add the necessary logic to handle successful and unsuccessful login attempts:
@app.route('/login', methods=['GET', 'POST'])
def login():
if request.method == 'GET':
return render_template('login.html')
elif request.method == 'POST':
username = request.form['username']
password = request.form['password']
conn = mysql.connect()
cursor = conn.cursor()
cursor.execute("SELECT * FROM users WHERE username = %s AND password = %s", (username, password))
result = cursor.fetchone()
conn.close()
if result:
return "Login successful"
else:
return "Invalid credentials"
Conclusion
Creating a login page using Flask and MySQL is a straightforward process that can be customized to fit your specific needs. In this article, we covered the basics of setting up Flask and MySQL, creating the login page, and authenticating users against a MySQL database.
Remember to always handle user authentication and password storage with care, using secure practices such as hashing and salting passwords. Additionally, consider adding additional security measures such as two-factor authentication to further protect user accounts.
By combining Flask and MySQL, you can create a robust and secure login page that provides a seamless user experience. So go ahead and start building your own login page using these powerful tools!
