Flask Application with SQLAlchemy: How to Handle Concurrent Updates Without Locking?
Can someone help me understand I'm developing a Flask application with SQLAlchemy and I'm working with issues with concurrent updates to the same row in the database. My current setup uses SQLite for development, and I’m seeing `OperationalError: database is locked` when multiple requests try to update the same record simultaneously. I'm using the following approach to update a record: ```python from flask import Flask, request, jsonify from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///test.db' db = SQLAlchemy(app) class Item(db.Model): id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(50)) quantity = db.Column(db.Integer) @app.route('/update_item/<int:item_id>', methods=['POST']) def update_item(item_id): data = request.json item = Item.query.get(item_id) if item: item.quantity += data['quantity'] db.session.commit() return jsonify({'message': 'Item updated successfully'}), 200 return jsonify({'message': 'Item not found'}), 404 ``` I’ve tried using `db.session.rollback()` in the exception block to handle the behavior, but it seems that it doesn’t resolve the locking scenario. Additionally, I am considering switching to PostgreSQL for production, but I would like to understand how to properly handle this in SQLite first. Is there a better way to manage concurrent updates without running into locking issues? Would using a different isolation level help, or should I explore using optimistic concurrency control? Any guidance would be appreciated! This is part of a larger CLI tool I'm building. What's the best practice here? This is part of a larger CLI tool I'm building. Thanks, I really appreciate it!