The two methods you've mentioned are effectively equivalent - either way you've got a unique identifier for "the record at the checkout time" effectively. I don't have any particular view on which is better, although a timestamp obviously gives you the added benefit of data about when the record was valid.
An alternative is to remember what the previous values were, and only allow an update if they match - that way if user A started editing a record, then user B goes in and changes something, then changes it back, user A's edits are still valid.
The term for these techniques is optimistic locking (or optimistic concurrency control).
There is actually a third method. To do the update, issue an update statement of this form:
UPDATE table SET update_field = new_value
WHERE db_pk = my_pk // assume primary key immutable
AND update_field = original_field_value
where original_field_value is the value of the field before the update was attempted. This update will fail if someone else has modified update_field, unless they have changed it to the same value that you have.
You're describing Optimistic Locking, a valid and useful technique.
See references here.
Either method is valid for checking.
As to which is the best you have to look at the size of your app and how long it will take to implement each one. So if this is only ever going to happen occasionally then I'd prob go for the quicker solution and implement the timestamp option.
If you want something more detailed google concurrency - heres an article to start with - concirrency
I am using the first option. Update the timestamp on each update. So at the time of update we check the equality of the timestamp.
乐观和悲观的术语是否敲响了警钟。这是解决您所描述问题的两种公认方法。听起来您在 Web 环境中工作。在这种情况下，前一个选项（乐观锁定）更合适。您已经继续描述了这通常是如何实现的。通常使用时间戳或版本号来检查自检索记录以来记录是否已更新。要考虑的另一件事是让您的用户知道基础数据发生了变化，并可能让他们选择在他们尝试保存的内容和其他用户保存的内容之间进行选择。这种选择实际上取决于业务规则是什么。