Transaction concluded

Four characteristics of transactions:
ACID
Atomicity: As the smallest execution unit, transactions are either all executed or not executed at all.
Consistency: The execution of a transaction causes the database to transition from one correct state to another.
Isolation: Transactions do not affect each other.
Durability: After a transaction is submitted correctly, its results will be stored in the database forever, even if there are other failures after the transaction is committed, the transaction results will be saved.
Transaction isolation level:
Read uncommit: Read uncommitted transaction data.(dirty read, non-repeatable read, phantom read)
read commit : Read the data of the committed transaction.(non-repeatable read, phantom read)
repeat read : The data read multiple times is the same.(phantom reading)
searial : Serialization, the execution of one thing by one thing.