If you complete your purchase process by the deadline, the seat is yours.
If you fail to complete the purchase by then - either because you go out to lunch or are just too slow in entering your information - the seat is "unlocked" and returned to the general pool. NET does not offer any built-in support for pessimistic concurrency control.
If you are ordering a ticket to a concert or plane flight online, it's important that from the time you pick your seat to the time you place your order and provide your payment information that some other user doesn't sneak in and take the seat you're ordering.
She clicks the Edit button and starts to make her change.
This article is one in a series of articles on ASP. This type of behavior is known as "last write wins" and is the default behavior for web applications.
"Last write wins" is sufficient in applications where it is very rare for two users to be simultaneously working on the same data.
Such draconian forms of concurrency control are referred to as pessimistic concurrency control.
With pessimistic concurrency control there needs to be some mechanism where a user can lock a particular row or an entire database table and say, essentially, "No one can modify these records until I'm done!