PHP mysqli_rollback() Function: Usage and Examples

Rolls back the active transaction on the connection.

The examples focus on the operation itself, including the important distinction: mysqli_commit makes transaction writes permanent.

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. Uses explicit transaction boundaries and transaction-capable tables.

<?php
$link = mysqli_connect(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
mysqli_set_charset($link, 'utf8mb4');
$selectedId = 7;
mysqli_begin_transaction($link);
$statement = mysqli_prepare($link, "UPDATE users SET active = 1 WHERE id = ?");
mysqli_stmt_bind_param($statement, "i", $selectedId);
mysqli_stmt_execute($statement);
mysqli_rollback($link);

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. Uses explicit transaction boundaries and transaction-capable tables.

<?php
$link = mysqli_connect(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
mysqli_set_charset($link, 'utf8mb4');
$selectedId = 12;
mysqli_begin_transaction($link);
$statement = mysqli_prepare($link, "UPDATE users SET active = 1 WHERE id = ?");
mysqli_stmt_bind_param($statement, "i", $selectedId);
mysqli_stmt_execute($statement);
mysqli_rollback($link);

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. Uses explicit transaction boundaries and transaction-capable tables.

<?php
$link = mysqli_connect(getenv('DB_HOST') ?: '127.0.0.1', getenv('DB_USER') ?: 'app', getenv('DB_PASSWORD') ?: '', getenv('DB_NAME') ?: 'demo');
mysqli_set_charset($link, 'utf8mb4');
$selectedId = 24;
mysqli_begin_transaction($link);
$statement = mysqli_prepare($link, "UPDATE users SET active = 1 WHERE id = ?");
mysqli_stmt_bind_param($statement, "i", $selectedId);
mysqli_stmt_execute($statement);
mysqli_rollback($link);

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

Cannot undo operations that were committed or DDL with implicit commits.

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

• Rolls back the active transaction on the connection.
• Cannot undo operations that were committed or DDL with implicit commits.
• mysqli_commit makes transaction writes permanent.

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