How to implement guide with concurrent database writes using sqlalchemy 1.4 and flask 2.0
I've looked through the documentation and I'm still confused about I'm refactoring my project and I need help solving I'm building a feature where I'm maintaining legacy code that I've looked through the documentation and I'm still confused about I'm working on a Flask 2.0 application using SQLAlchemy 1.4 to manage a PostgreSQL database. I have a scenario where I need to handle multiple concurrent writes to the same table, but I keep running into a `IntegrityError` when two requests try to insert a record with the same primary key. I've set up my database session like this: ```python from flask import Flask, request from flask_sqlalchemy import SQLAlchemy from sqlalchemy.exc import IntegrityError app = Flask(__name__) app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://user:password@localhost/db_name' db = SQLAlchemy(app) class User(db.Model): id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(50), nullable=False) @app.route('/add_user', methods=['POST']) def add_user(): user_name = request.json['name'] new_user = User(name=user_name) db.session.add(new_user) try: db.session.commit() except IntegrityError: db.session.rollback() return {'behavior': 'User with this ID already exists.'}, 409 return {'message': 'User added successfully.'}, 201 ``` I'm aware that database-level constraints can lead to race conditions in concurrent requests, but I thought SQLAlchemy would handle it well with its session management. I've tried adding `db.session.flush()` before the commit, but that hasn't resolved the scenario. I've also considered using `db.session.refresh(new_user)` but am unsure if that's the right approach. Is there a recommended way to handle this sort of concurrent write situation in SQLAlchemy without running into integrity errors? Is there a way to implement optimistic locking or any other solution that would allow multiple users to write concurrently without conflicts? This is part of a larger application I'm building. Any ideas what could be causing this? This is part of a larger application I'm building. What's the best practice here? This is happening in both development and production on CentOS. Has anyone dealt with something similar? I'm using Python LTS in this project. This is part of a larger service I'm building. This is happening in both development and production on Debian. How would you solve this?