MySQL lock mechanism (example)

Let's take an example , An airplane booking system has two ticket offices a and B , Originally there were A=16 Tickets , At this time, a ticket office sells one A <-- A-1, The remaining 15 Zhang , At this time, the ticket office B also sells one A <-- A-1, The remaining 15 Zhang , Should have been left 14 Zhang's , This means that multiple transactions modify the same data at the same time , A situation that results in inconsistent data

The problem of data inconsistency caused by concurrent operations includes loss operations 、 It can't be read repeatedly 、 read “ dirty ” data

mysql Locking mechanism is used to ensure the effectiveness of concurrent operations and data consistency

The process of locking , It's just that a is modifying A When , Get a lock first , There are many kinds of locks , The functional characteristics are also different , After you get it, you will A Lock it up , So others can't be right A Modified , Only after the execution of Party A's affairs, right A Others can only get the lock after the lock , Then on A To lock , Under modification , This is it. mysql Lock mechanism .

（ Personal understanding ）