The lock understanding in MySQL

1. Purpose: Resolve client concurrent access to your conflict issues
2, the Classification of locks
1. Lock type
1. Read lock (Shared lock)
Query (SELECT): After a lock is read, the table record cannot be changed, but can be queried.
2. Write lock (mutex, exclusive lock)
Update: After the lock is written, no one else can check it.
2, the size of the lock
1, row-level lock: Innodb (Storage engine)
Select: Add read lock, lock 1 rows
Update: Add write lock, lock 1 rows
2. Table level Lock: MyISAM
Select: Read lock, lock 1 sheets, other people can only check, can not change
Update: Add write lock, lock 1 table, other people can not change and can not check

The lock understanding in MySQL