How to maintain data consistency in for update operation in nosql?

Question

For example, we have a table like below

car_id, car_name, car_status, engine
100,    car1,     running,    A
200，   car2,     stop,       B

The business logic is engine can not be updated while car_status is running

The most obvious step is

1. Check if status is running,
2. Update if status is not running

The problem is that someone may change the status to running during the time between step 1 and 2.

How do you to prevent this in RDBMS and mongo?

Answer 1

我认为您只需要保留一种在应用程序中更新car_status的方法，并将该函数作为更新car_status的唯一方法公开（您可以在数据库中创建一个对此表或集合具有写权限的用户，这将强制您必须始终仅使用该user_id来运行此更新操作，当然，这在从应用程序执行时同样适用。）