计算库存最大值

@@ -56,16 +56,20 @@ class Cart extends Api
         $spec_sku  = new Litestoregoodsspec();
         $spec_info = $spec_sku->where('goods_spec_id', $sku_id)->find();
         if ($cart) {
-            if ( $number > $spec_info['stock_num']) {
+            if ($number > $spec_info['stock_num']) {
                 $this->error('库存不足');
+            } else {
+                $model->where($where)->update(['number'=>$number]);
             }
-            $cart->setInc('number', $number);
+
         } else {
             if ($spec_info['stock_num'] > $number) {
                 $this->error('库存不足');
+            } else {
+                $data['number'] = $number;
+                $model->isUpdate(false)->save($data);
             }
-            $data['number'] = $number;
-            $model->isUpdate(false)->save($data);
+
         }
         $this->success('SUCCESS');
     }