diff --git a/src/main/resources/db/migration/V12__fix_order_item_foreign_key_safe.sql b/src/main/resources/db/migration/V12__fix_order_item_foreign_key_safe.sql
new file mode 100644
index 0000000..23b66a7
--- /dev/null
+++ b/src/main/resources/db/migration/V12__fix_order_item_foreign_key_safe.sql
@@ -0,0 +1,15 @@
+-- 安全处理订单明细外键约束（使用IF EXISTS避免重复执行报错）
+-- 先检查约束是否存在，存在则删除
+DO $$
+BEGIN
+    IF EXISTS (
+        SELECT 1 FROM information_schema.table_constraints 
+        WHERE constraint_name = 'order_items_product_id_fkey' 
+        AND table_name = 'order_items'
+    ) THEN
+        ALTER TABLE order_items DROP CONSTRAINT IF EXISTS order_items_product_id_fkey;
+    END IF;
+END $$;
+-- 重新添加外键约束（不级联删除）
+ALTER TABLE order_items ADD CONSTRAINT order_items_product_id_fkey 
+    FOREIGN KEY (product_id) REFERENCES products(product_id);
\ No newline at end of file