MySQL Transaction (ii)--Control statement usage

Transaction control

In general, MySQL turns on the transaction autocommit feature by default, and each SQL execution commits the transaction. You can turn off the transaction autocommit feature by using the following statement.

Show session variables like ' autocommit ', set @ @autocommit = 0;show Session variables like ' autocommit ';

1. Start of transaction

Begin or start transaction;

2. Transaction Submission

Commit or commit work;

3. Rollback

Rollback or rollback work;

4, Save point settings

SavePoint identification;

5. Roll back to SavePoint

Rollback to SavePoint logo;

6. Delete the savepoint

Release savepoint identification.

Transaction isolation

read-uncommitted READ UNCOMMITTED

Read-committed Read submitted

Repeatable-read Repeat Read

Serialization of SERIALIZABLE

	Dirty Read	Non-stressed	Phantom reading
read-uncommitted	Y	Y	Y
read-committed	N	Y	Y
Repeatable-read	N	N	Y
SERIALIZABLE	N	N	N

Dirty reads: Reading data is another transactional process data, and reading it may be wrong.

Non-stressed: the second read data content is different from the first read data content. (No read transaction process data exists)

Phantom reads: The number of rows of data read the second time is more or less than the first read. (No read transaction process data exists)

MySQL Transaction (ii)--Control statement usage