A Subtle Laravel Pitfall: Dispatching Events Inside Database Transactions

A Subtle Laravel Pitfall: Dispatching Events Inside Database Transactions

When working with Laravel, it is easy to fall into a subtle but significant trap: dispatching events from within a database transaction and assuming everything is safe and synchronized.
The reality is that Laravel will dispatch the event immediately—even if the database transaction later fails and rolls back.

This creates a serious inconsistency. For example:

  • The database rolls back because the transaction fails.

  • But the event listener already executed.

  • Emails may have been sent, notifications triggered, or jobs dispatched for data that never actually existed.

This disconnect can lead to data integrity issues and unexpected application behavior.

A Simple Analogy

Imagine you are in a restaurant:

  • The waiter (Laravel) receives the order from the cashier (database transaction).

  • Before the cashier saves the order into the system, the waiter goes to the kitchen and tells the chef to start cooking (event listener).

  • Two seconds later, the cashier says:
    “Stop, the customer canceled the order.”

  • But the meal is already being prepared.

This is exactly what happens when you dispatch an event before the database transaction commits.

What Actually Happens in Laravel

When you fire an event inside a transaction:

DB::transaction(function () {
    User::create($data);
    event(new UserCreated());
});

The event listener executes immediately.
If the transaction later fails, the database rolls back, but the listener has already acted—sending an email, creating a job, or updating a system based on data that was never saved.

This creates side effects for records that do not exist.

The Proper Solution

Laravel provides two reliable approaches to ensure your event logic executes only after the database transaction has committed successfully.

1. Use DB::afterCommit()

DB::transaction(function () {
    User::create($data);

    DB::afterCommit(function () {
        event(new UserCreated());
    });
});

This callback will run only if the transaction is committed successfully. If a rollback occurs, nothing is executed.

2. Enable afterCommit on the Listener

Laravel also allows you to configure the listener to run only after the commit:

class SendWelcomeEmail
{
    public $afterCommit = true;

    public function handle(UserCreated $event)
    {
        // Logic that depends on committed data
    }
}

With $afterCommit = true, the listener is executed only when the transaction is confirmed and committed.

Conclusion

Dispatching events inside database transactions may look harmless, but it can produce inconsistent behavior and unwanted side effects.
By using DB::afterCommit() or enabling $afterCommit in the listener, you ensure that your application remains consistent, predictable, and aligned with the actual database state.

These practices are essential for building reliable, production-grade Laravel applications.