flask mysql models

Flask MySQL Models

When building a web application with Flask, it's common to use a database to store and retrieve data. MySQL is a popular choice for many developers due to its reliability and scalability. In this article, we will explore how to create models in Flask that interact with a MySQL database.

Setting up Flask and MySQL

Before we can create models in Flask that interact with a MySQL database, we need to install the necessary packages. We can install Flask and Flask-MySQL by running the following commands:

pip install Flask
pip install Flask-MySQL

Next, we need to set up our Flask application and configure it to use a MySQL database. We can do this by creating a config.py file with the following content:

# config.py

MYSQL_HOST = 'localhost'
MYSQL_USER = 'root'
MYSQL_PASSWORD = 'password'
MYSQL_DB = 'mydatabase'

We then need to create our Flask application and configure it to use the settings from our config.py file:

# app.py

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config.from_pyfile('config.py')
db = SQLAlchemy(app)

Creating Models

Now that we have set up our Flask application and configured it to use a MySQL database, we can create models that represent our database tables. Models in Flask are usually defined as classes that inherit from db.Model. Each attribute of the class corresponds to a column in the database table.

Let's create a simple User model that represents a table with columns for id, username, and email:

# models.py

from app import db

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(50), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)

We can then create the database tables by running the following commands in a Python shell:

from app import db
from models import User

db.create_all()

Querying the Database

With our models set up, we can now query the database to retrieve and manipulate data. We can use SQLAlchemy's query methods to interact with the database. For example, to retrieve all users from the User table, we can run the following code:

all_users = User.query.all()

We can also filter the results based on certain criteria. For example, to retrieve a user with a specific id, we can run the following code:

user = User.query.filter_by(id=1).first()

Conclusion

In this article, we have explored how to create models in Flask that interact with a MySQL database. By defining models as classes that inherit from db.Model and using SQLAlchemy's query methods, we can easily interact with our database and retrieve and manipulate data. Flask and MySQL make a powerful combination for building web applications that require a reliable and scalable database backend.

---

classDiagram
    User <|-- Post
    User : id
    User : username
    User : email
    Post : id
    Post : title
    Post : content

pie
    title Flask MySQL Models
    "Setting up Flask and MySQL" : 25
    "Creating Models" : 25
    "Querying the Database" : 25
    "Conclusion" : 25

In conclusion, creating models in Flask to interact with a MySQL database is a crucial step in building web applications. By following the steps outlined in this article, developers can easily set up their Flask application, define models, and query the database to retrieve and manipulate data. Flask and MySQL offer a powerful and reliable solution for storing and managing data in web applications.