新增商品問題修正

database/migrations/2025_12_31_172200_make_conversion_rate_nullable.php

@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('products', function (Blueprint $table) {
+            $table->decimal('conversion_rate', 10, 4)->nullable()->default(null)->change();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('products', function (Blueprint $table) {
+            $table->decimal('conversion_rate', 10, 4)->nullable(false)->default(1)->change();
+        });
+    }
+};