Correct error in doubler class. Add artisan command to sync doublers.

app/Console/Commands/SyncDoublers.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace App\Console\Commands;
+
+use App\Models\Doubler;
+use App\Models\Event;
+use Illuminate\Console\Command;
+
+class SyncDoublers extends Command
+{
+    /**
+     * The name and signature of the console command.
+     *
+     * @var string
+     */
+    protected $signature = 'doublers:sync {event? : Optional event ID}';
+
+    /**
+     * The console command description.
+     *
+     * @var string
+     */
+    protected $description = 'Update doublers table based on current entries';
+
+    /**
+     * Execute the console command.
+     */
+    public function handle()
+    {
+        if ($eventId = $this->argument('event')) {
+            $event = Event::findOrFail($eventId);
+            Doubler::syncForEvent($event);
+            $this->info("Synced doublers for event {$event->name}");
+        } else {
+            Doubler::syncDoublers();
+            $this->info('Synced doublers for all events');
+        }
+    }
+}

app/Models/Doubler.php

@@ -69,6 +69,7 @@ class Doubler extends Model
                 ],
                 [
                     'accepted_entry' => $acceptedEntryId,
+                    'entry_count' => $student->entriesForEvent($eventId)->count(),
                 ]
             );
         }