在Laravel中运行事务时，具有InnoDB的MySQL实例是否锁定行？

Question

I am trying to implement an in-app credit system using Laravel 4.2. I am planning to store the user credit in a table. As I want an user credit to be free of race conditions, I researched the internet for a proper implementation. Some of the answers were suggesting that if I would use Laravel transactions + MySQL instance with InnoDB there won't be any race conditions. Some answers suggested me to use lockForUpdate, but I fear an improper use might lead to deadlock.

How should I implement it? Am I safe if I just use transactions?

Answer 1

I went through the source code and found out that Laravel 4.2's transactions are based on PDO transactions (eg. PDO::beginTransaction). Using PDO transactions with MySQL has this kind of behavior. As the ACID rules are followed, I am assuming that I am safe for my use case.