How do you manage database transactions with DB::transaction and handle Deadlocks?

Short answer

Transactions make operations atomic and roll them back on failure; DB::transaction accepts an argument that sets how many times to retry automatically after a Deadlock.

Explanation

Transactions prevent partial failures in financial operations and reservations. Concurrent transactions can lock rows in conflicting orders, causing a database Deadlock. DB::transaction(callback, attempts: 5) automatically retries transient Deadlocks without showing the error to the client.

Code example

DB::transaction(function () use ($from, $to, $amount) {
    $from->decrement('balance', $amount);
    $to->increment('balance', $amount);
}, 5); // 5 Retries when Deadlock

Common mistakes

• Sending emails or making external HTTP requests inside DB::transaction; these actions repeat on each retry and cannot be undone by a Rollback.

Follow-up questions

• How do you efficiently perform bulk inserts and updates (Upsert) in Eloquent with one query?

Sources

• Laravel docs — Database Transactions