How can I implement a database rollback in Flask?

How can I implement a database rollback in Flask?

To implement a database rollback in Flask, you can use the rollback() method of the session object. This is typically done within a try-except block.

Can you show me a code example?

Sure! Here's a simple example:

from flask import Flask, request
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///example.db'
db = SQLAlchemy(app)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50))

@app.route('/add_user', methods=['POST'])
def add_user():
    try:
        new_user = User(name=request.json['name'])
        db.session.add(new_user)
        db.session.commit()
    except Exception as e:
        db.session.rollback()
        return {'error': str(e)}, 400
    return {'message': 'User added successfully!'}, 201

What happens if I don't use rollback?

If you don't use rollback, any changes made during the transaction will be committed, even if an error occurs. This can lead to inconsistent data.