Seed Laravel factory data with an incrementing date

We use this technique in some of our courses. Check them out, you'll find plenty more tricks like this too.

Let's imagine we have a Message model. A seeder using a factory would look like this:

public function run(): void
{
    Message::factory()
        ->times(5000)
        ->create();
}

When this seeder runs and creates 5000 records, the created_at date will be pretty much the same for every record, so unfortunately, when we order the records with orderBy or latest, it won't represent any real order.

How to increment created_at when seeding¶

We can leverage sequences in factories that run for every record being created.

Here's how I usually implement these:

public function run(): void
{
    Message::factory()
        ->times(5000)
        ->sequence(function (Sequence $sequence) {
            return [
                'created_at' => now()->subHour($sequence->index)
            ];
        })
        ->create();
}

The sequence callback gives us a Sequence object for every 5000 records we generate here. Because this object contains an index (starting at 0), we can modify the created_at date for every record by subtracting an hour.

Feel free to update the state inside the sequence to modify the created_at date in any way. Most importantly, all our records will now have an orderable created_at date!