update sku mapping

backend/migrations/2026_04_14_120000_make_platform_product_id_nullable.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+use Hyperf\Database\Schema\Schema;
+use Hyperf\Database\Schema\Blueprint;
+use Hyperf\Database\Migrations\Migration;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('skus_mapping', function (Blueprint $table) {
+            $table->text('platform_product_id')->nullable()->change();
+        });
+
+        // 删除原有唯一约束（如果存在）并创建部分唯一索引
+        $connection = Schema::getConnection();
+        $connection->statement('DROP INDEX IF EXISTS uk_platform_product');
+        $connection->statement(
+            'CREATE UNIQUE INDEX uk_platform_product ON skus_mapping (platform_id, platform_product_id) WHERE platform_product_id IS NOT NULL'
+        );
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        $connection = Schema::getConnection();
+        $connection->statement('DROP INDEX IF EXISTS uk_platform_product');
+        $connection->statement(
+            'CREATE UNIQUE INDEX uk_platform_product ON skus_mapping (platform_id, platform_product_id)'
+        );
+
+        Schema::table('skus_mapping', function (Blueprint $table) {
+            $table->text('platform_product_id')->nullable(false)->change();
+        });
+    }
+};