Question

我在一个衬衫店的mvc 4应用程序中有一个SubCategory模型，我想在运行我的应用程序时使用种子数据填充数据库，我收到错误消息：“序列中没有匹配的元素”

我的代码：

    var subCategories = new List<SubCategory>
        {
    new SubCategory{Category = categories.Single(s => s.Name == "Animals") , Name "Animal Prints"},
    new SubCategory{Category = categories.Single(s => s.Name == "Animals") , Name = "Bugs"},
        };

Answer 1

原因是您的类别中没有任何名称为“动物”的条目如果你想检查它

   var categorie = categories.where(s => s.Name == "Animals").SingleOrDefault();

   if(categories == null)
   {
     // db is not seeded with categories do something
   }
   else
   {     

        var subCategories = new List<SubCategory>
        {
           new SubCategory{Category = categorie  , Name "Animal Prints"},
           new SubCategory{Category = categorie  , Name = "Bugs"},
        };
   }

序列不包含匹配元素

1 个答案: