The realization principle of MySQL transaction isolation level

The database isolation level is mainly to create a view, and the logical result of the view shall prevail when accessing.

• Under the "read uncommitted" isolation level, the latest value on the record is directly returned, without the concept of view;
• Under the "read commit" isolation level, this view is created when each SQL statement starts to execute.
• Under the "repeatable read" isolation level, this view is created when the transaction starts, and this view is used throughout the existence of the transaction.
• Under the "serialization" isolation level, locks are used directly to avoid parallel access.