MySQL Transactions

MySQL transactions are an essential feature of the popular relational database management system (RDBMS) MySQL. Transactions provide a way to group a sequence of database operations into a single unit of work that is executed atomically, ensuring data integrity and consistency.

A transaction is a logical unit of work that consists of one or more database operations, such as inserts, updates, or deletes. These operations are treated as a single, indivisible entity, meaning they are either all committed to the database or none of them are. This property of atomicity guarantees that the database remains in a consistent state even in the presence of failures or concurrent access.

ACID properties

The concept of a transaction revolves around the ACID properties:

Atomicity: All operations within a transaction are treated as a single unit. If any operation fails or encounters an error, the entire transaction is rolled back, and the database reverts to its previous state.

Consistency: Transactions ensure that the database transitions from one consistent state to another. Constraints, such as referential integrity or uniqueness, are maintained throughout the transaction.

Isolation: Transactions provide isolation from other concurrent transactions. Each transaction operates as if it were the only transaction executing, preventing interference or inconsistent results caused by concurrent modifications.

Durability: Once a transaction is committed, its changes are permanently saved to the database, even in the event of a system failure or restart. The changes become durable and can be considered a permanent part of the database.


MySQL provides a set of commands to work with transactions:

BEGIN or START TRANSACTION: Begins a new transaction explicitly. Any subsequent database operations form part of the transaction until it is either committed or rolled back.

COMMIT: Commits the transaction, making all changes within the transaction permanent. Once committed, the changes become visible to other transactions.

ROLLBACK: Rolls back the transaction, undoing all changes made within the transaction. After a rollback, the database returns to its previous state before the transaction began.

SAVEPOINT: Defines a savepoint within a transaction. Savepoints allow you to mark a specific point in a transaction, enabling you to roll back to that point without undoing the entire transaction.


SET autocommit = { 0 | 1 }


UPDATE test SET name='tom' WHERE id=1;

Transactions are crucial in scenarios where multiple database operations need to be performed together as a unit, such as financial transactions, inventory management, or complex data modifications. By ensuring data integrity and consistency, transactions provide reliability and accuracy in database operations.

It’s important to note that not all storage engines in MySQL support transactions. The commonly used InnoDB storage engine is transactional and provides support for ACID-compliant transactions.

In summary, MySQL transactions are a powerful mechanism that allows developers to maintain data integrity, consistency, and reliability in database operations. By adhering to the ACID properties, transactions ensure that the database remains in a valid state even in the face of failures or concurrent access, making them an essential feature for many applications that rely on MySQL.