Trouble with threading and SQLite in Python 3.9 causing database locked scenarios
This might be a silly question, but I'm stuck on something that should probably be simple... I'm working with a `sqlite3.OperationalError: database is locked` behavior when using threading to handle database operations in Python 3.9. I'm using the `sqlite3` library to interact with a local SQLite database. I have a simple web server built using Flask that launches a new thread to handle incoming requests and perform database operations. Here’s a simplified version of my code: ```python import sqlite3 import threading from flask import Flask, request app = Flask(__name__) def db_query(query): conn = sqlite3.connect('mydatabase.db') cursor = conn.cursor() cursor.execute(query) conn.commit() cursor.close() conn.close() @app.route('/update', methods=['POST']) def update_database(): data = request.json query = f"UPDATE my_table SET value = '{data['value']}' WHERE id = {data['id']}" thread = threading.Thread(target=db_query, args=(query,)) thread.start() return 'Update initiated', 202 if __name__ == '__main__': app.run(debug=True) ``` The scenario arises when multiple requests are made simultaneously to the `/update` endpoint. When this happens, I frequently get the `database is locked` behavior. I’ve tried using a connection pool, but that didn’t help. I've also looked into using `sqlite3.connect('mydatabase.db', check_same_thread=False)` to allow multiple threads to use the same connection, but this doesn't seem to resolve the scenario either. I’m aware that SQLite has limitations when it comes to concurrent writes. Is there a recommended pattern to follow when working with Flask, SQLite, and threading that might help in avoiding this behavior? Or should I consider using a different approach or database? Any insights would be greatly appreciated! What's the best practice here?