PHP Mysqli::rollback() Method: Usage and Examples

Cancels changes pending in an active transaction.

The examples focus on the operation itself, including the important distinction: commit makes the transaction's changes durable.

What It Does

Use the examples below to observe the behavior on a small dataset before extending it to application code.

Syntax and Return Value

Mysqli::rollback(...) — requires the corresponding optional extension

The displayed signature describes the API or identifies any correction or optional dependency. When a parameter is optional, supply it only when the task requires it.

Example 1: Basic Use

Examples assume a demo database containing users(id, email, active), products(id, name, price), and orders(id, user_id, total) as required by the query.

<?php
$mysqli = new mysqli(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
$mysqli->set_charset('utf8mb4');
$selectedId = 7;
$mysqli->begin_transaction();
try { $mysqli->query("UPDATE users SET active = 0 WHERE id = " . (int) 7); throw new RuntimeException("Cancellation requested"); } catch (Throwable $e) { $mysqli->rollback(); }

This example is meant for a configured application environment; output depends on the installed extension, external service, or database contents.

Example 2: Checking Behavior

Examples assume a demo database containing users(id, email, active), products(id, name, price), and orders(id, user_id, total) as required by the query.

<?php
$mysqli = new mysqli(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
$mysqli->set_charset('utf8mb4');
$selectedId = 12;
$mysqli->begin_transaction();
try { $mysqli->query("UPDATE users SET active = 0 WHERE id = " . (int) 12); throw new RuntimeException("Cancellation requested"); } catch (Throwable $e) { $mysqli->rollback(); }

This example is meant for a configured application environment; output depends on the installed extension, external service, or database contents.

Example 3: Practical Example

Examples assume a demo database containing users(id, email, active), products(id, name, price), and orders(id, user_id, total) as required by the query.

<?php
$mysqli = new mysqli(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
$mysqli->set_charset('utf8mb4');
$selectedId = 24;
$mysqli->begin_transaction();
try { $mysqli->query("UPDATE users SET active = 0 WHERE id = " . (int) 24); throw new RuntimeException("Cancellation requested"); } catch (Throwable $e) { $mysqli->rollback(); }

This example is meant for a configured application environment; output depends on the installed extension, external service, or database contents.

Important Behavior and Edge Cases

Rollback does not reverse MySQL DDL that performed an implicit commit.

This API is supplied by an optional extension that is not installed in the local test runtime, or requires a different PHP version. The example must be verified in a matching environment.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Cancels changes pending in an active transaction.
• Rollback does not reverse MySQL DDL that performed an implicit commit.
• commit makes the transaction's changes durable.

Use Mysqli::rollback when its documented behavior matches the problem. Test the relevant edge cases in your own runtime before deploying it.