↩️ MySQL ROLLBACK

? Quick Overview

ROLLBACK is a Transaction Control Language (TCL) command used in MySQL to undo changes made in the current transaction. It restores the database to the last committed state and is mainly used to prevent unwanted data changes.

? Key Concepts

Works only with transactional storage engines like InnoDB
Undoes INSERT, UPDATE, and DELETE operations
Cannot rollback after COMMIT
DDL statements like CREATE or DROP auto-commit

? Syntax & Theory

A transaction is a sequence of SQL statements executed as a single logical unit. If something goes wrong, ROLLBACK reverts all changes made during the transaction.

? View Code Example

-- Start a new transaction
START TRANSACTION;

-- Insert a new record
INSERT INTO accounts (name, balance)
VALUES ('Rahul', 5000);

-- Undo the transaction
ROLLBACK;

? Live Output / Explanation

What happens?

The record for Rahul is temporarily added
ROLLBACK cancels the insert operation
No data is permanently saved in the table

? Tips & Best Practices

Always use transactions for critical data changes
Verify engine type using SHOW TABLE STATUS
Use ROLLBACK during testing and debugging
Combine with SAVEPOINT for partial rollbacks

? Try It Yourself

Create a table with InnoDB engine
Start a transaction
Insert multiple rows
Execute ROLLBACK
Verify that no rows were saved