Create a command in Laravel:

php artisan make:command CommandName

Example with vocabularies table:

<?php

namespace App\Console\Commands;

use Illuminate\Console\Command;
use App\Models\Vocabulary;
use Illuminate\Support\Str;
use Illuminate\Support\Facades\DB;

class AddVocabularySlug extends Command
{
    /**
     * The name and signature of the console command.
     *
     * @var string
     */
    protected $signature = 'voc:update-slug';

    /**
     * The console command description.
     *
     * @var string
     */
    protected $description = '';

    /**
     * Execute the console command.
     */
    public function handle()
    {
        $vocabularies = Vocabulary::whereNull('slug')->get()->map(function ($vocabulary) {
            echo "Mapping vocabulary id: {$vocabulary->id}\n";
            return [
                'id' => $vocabulary->id,
                'slug' => Str::substr(Str::slug($vocabulary->mean), 0, 255)
            ];
        })->toArray();
        echo "Total vocabularies: " . count($vocabularies) . "\n";
        $this->updateBatch('vocabularies', $vocabularies);
    }

    function updateBatch($tableName = "", $multipleData = array())
    {

        if ($tableName && !empty($multipleData)) {

            // column or fields to update
            $updateColumn = array_keys($multipleData[0]);
            $referenceColumn = $updateColumn[0]; //e.g id
            unset($updateColumn[0]);
            $whereIn = "";

            $q = "UPDATE " . $tableName . " SET ";
            foreach ($updateColumn as $uColumn) {
                $q .=  $uColumn . " = CASE ";

                foreach ($multipleData as $data) {
                    $q .= "WHEN " . $referenceColumn . " = " . $data[$referenceColumn] . " THEN '" . $data[$uColumn] . "' ";
                }
                $q .= "ELSE " . $uColumn . " END, ";
            }
            foreach ($multipleData as $data) {
                echo "Processing vocabulary id: {$data[$referenceColumn]}\n";

                $whereIn .= "'" . $data[$referenceColumn] . "', ";
            }
            $q = rtrim($q, ", ") . " WHERE " . $referenceColumn . " IN (" .  rtrim($whereIn, ', ') . ")";

            echo "Updating\n";

            // Update  
            return DB::update(DB::raw($q));
        } else {
            return false;
        }
    }
}