Handling MySQL Data Consistency Issues with Mobile App Synchronization
I'm updating my dependencies and I'm following best practices but Currently developing a mobile application that syncs user data with a MySQL database remotely. I've configured the backend to manage updates effectively, but I'm running into issues with data consistency when multiple users simultaneously modify the same records. The app architecture uses Node.js for the API layer alongside Sequelize as the ORM for MySQL. Users have been reporting data overrides, leading to lost updates. After researching, I decided to implement optimistic locking, as documented in Sequelize’s guides. Here’s the relevant part of the code: ```javascript const User = sequelize.define('User', { id: { type: Sequelize.INTEGER, primaryKey: true, autoIncrement: true, }, name: Sequelize.STRING, version: { type: Sequelize.INTEGER, defaultValue: 0, }, }, { timestamps: true }); // Update user function async function updateUser(userId, newName, currentVersion) { const result = await User.update({ name: newName, version: currentVersion + 1 }, { where: { id: userId, version: currentVersion } }); return result; } ``` Although the optimistic locking seems like the right approach, I'm still seeing instances where users overwrite each other's changes, which is puzzling. Could it be that the front end isn’t properly updating the `version` number after fetching the latest data? I’ve been using the following code to retrieve user data: ```javascript async function fetchUserData(userId) { return await User.findOne({ where: { id: userId } }); } ``` Additionally, I’ve enabled transactions in MySQL with the following configuration: ```sql SET autocommit = 0; START TRANSACTION; -- Your update queries here COMMIT; ``` With transactions, I expected a more controlled update flow, but the inconsistencies persist. Are there any best practices or design patterns I might be overlooking to ensure data integrity in this distributed setup? Have other developers faced similar challenges with mobile compatibility and data synchronization? Any insights or recommendations would be greatly appreciated. I'd really appreciate any guidance on this. Any ideas how to fix this? This is my first time working with Javascript 3.10. This is part of a larger web app I'm building.