update migrations

database/migrations/2021_09_06_014744_create_holdings_table.php

@@ -1,6 +1,7 @@
 <?php
 
 use App\Models\Portfolio;
+use App\Models\MarketData;
 use Illuminate\Support\Facades\Schema;
 use Illuminate\Database\Schema\Blueprint;
 use Illuminate\Database\Migrations\Migration;
@@ -16,13 +17,15 @@ class CreateHoldingsTable extends Migration
     {
         Schema::create('holdings', function (Blueprint $table) {
             $table->uuid('id')->primary(); 
-            $table->foreignIdFor(Portfolio::class, 'portfolio_id')->onDelete('cascade');
-            $table->string('symbol', 15);
+            $table->foreignIdFor(Portfolio::class, 'portfolio_id')->constrained()->onDelete('cascade');
+            $table->foreignIdFor(MarketData::class, 'symbol');
             $table->float('quantity', 12, 4);
             $table->float('average_cost_basis', 12, 4);
             $table->float('total_cost_basis', 12, 4)->nullable();
             $table->float('realized_gain_loss_dollars', 12, 4)->nullable();
             $table->float('dividends_earned', 12, 4)->nullable();
+            $table->timestamp('splits_synced_at')->nullable();
+            $table->timestamp('dividends_synced_at')->nullable();
             $table->timestamps();
         });
     }