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MySQL Tutorial - Ways to Start a New Transaction

By: FYIcenter.com

(Continued from previous topic...)

How To Start a New Transaction?

MySQL server offers two modes to manage transactions:

• Autocommit On - Default mode. Can be started with "SET AUTOCOMMIT = 1" command. In this mode, every single SQL statement is a new transaction. All changes will be committed at the end of the statement execution.
• Autocommit Off - Can be started with "SET AUTOCOMMIT = 0" command. In this mode, multiple SQL statements can be grouped into a single transaction.

When a client program starts a new connection session with the MySQL server, the client program can start a new transaction implicitly or explicitly in the following ways:

• In "Autocommit On" mode, every executable statement will implicitly start a new single-statement transaction.
• In "Autocommit Off" mode, the first executable statement of a new session will implicitly start a new multi-statement transaction.
• In "Autocommit Off" mode, the first executable statement after a previous transaction has been ended will implicitly start a new multi-statement transaction.
• In "Autocommit On" mode or "Autocommit Off" mode, "START TRANSACTION" will explicitly start a new multi-statement transaction.

(Continued on next topic...)

1. What Is a Transaction?
2. How To Start a New Transaction?
3. How To End the Current Transaction?
4. How To Create a Table for Transaction Testing?
5. How To Switch between Autocommit-On and Autocommit-Off Modes?
6. How To Find Out the Current Transaction Mode?
7. How To Start a New Transaction Explicitly?
8. How To Commit the Current Transaction?
9. How To Rollback the Current Transaction?
10. What Happens to the Current Transaction If a START TRANSACTION Is Executed?
11. What Happens to the Current Transaction If a DDL Statement Is Executed?
12. What Happens to the Current Transaction If the Session Is Ended?
13. What Happens to the Current Transaction If the Session Is Killed?
14. How Does MySQL Handle Read Consistency?
15. What Are Transaction Isolation Levels?
16. How To View and Change the Current Transaction Isolation Level?
17. What Is a Data Lock?
18. How To Experiment Data Locks?
19. How Long a Transaction Will Wait for a Data Lock?
20. What Happens to Your Transactions When ERROR 1205 Occurred?
21. What Is a Dead Lock?
22. How To Experiment Dead Locks?
23. What Happens to Your Transactions When ERROR 1213 Occurred?
24. What Are Impacts on Applications from Locks, Timeouts, and DeadLocks?