fix: 移除订单明细的级联删除，商品信息已冗余

src/main/resources/db/migration/V11__fix_order_item_foreign_key.sql

@@ -0,0 +1,4 @@
+-- 订单明细表外键移除级联删除（商品信息已冗余保存）
+ALTER TABLE order_items DROP CONSTRAINT IF EXISTS order_items_product_id_fkey;
+ALTER TABLE order_items ADD CONSTRAINT order_items_product_id_fkey 
+    FOREIGN KEY (product_id) REFERENCES products(product_id);

src/main/resources/db/migration/V9__fix_product_foreign_key.sql

@@ -1,4 +1,5 @@
--- 修改商品表外键约束，级联删除
+-- 修改商品表外键约束，级联删除（库存、库存流水）
+-- 但订单明细不级联删除，因为已冗余保存商品信息
 ALTER TABLE stock DROP CONSTRAINT IF EXISTS stock_product_id_fkey;
 ALTER TABLE stock ADD CONSTRAINT stock_product_id_fkey 
     FOREIGN KEY (product_id) REFERENCES products(product_id) ON DELETE CASCADE;
@@ -7,6 +8,7 @@ ALTER TABLE stock_flow DROP CONSTRAINT IF EXISTS stock_flow_product_id_fkey;
 ALTER TABLE stock_flow ADD CONSTRAINT stock_flow_product_id_fkey 
     FOREIGN KEY (product_id) REFERENCES products(product_id) ON DELETE CASCADE;
 
+-- 订单明细不再级联删除（已冗余保存商品信息）
 ALTER TABLE order_items DROP CONSTRAINT IF EXISTS order_items_product_id_fkey;
 ALTER TABLE order_items ADD CONSTRAINT order_items_product_id_fkey 
-    FOREIGN KEY (product_id) REFERENCES products(product_id) ON DELETE CASCADE;
+    FOREIGN KEY (product_id) REFERENCES products(product_id);