实体框架使用参数执行存储过程

您可以这样执行存储过程:

 using (var command = mainContext.Database.GetDbConnection().CreateCommand())
   {
        command.CommandType = System.Data.CommandType.StoredProcedure;
        command.CommandText = "dbo.RatingCalculator";

       var locationIdParam = new System.Data.SqlClient.SqlParameter("@locationId", System.Data.SqlDbType.Int);
       locationIdParam .Value = offer.locationId;

        //DO same for typeId parameter

          //Params to Parameters collection
          command.Parameters.Add(locationIdParam);

       command.Connection.Open();
       return (double)command.ExecuteScalar();
   }

Controllers\AnnouncesController.cs(127,37): error CS0120: An object reference is required for the non-static field, method, or property 'CalculateRating.CreateRating(OfferForCreate)

发生此错误是因为如果您声明 CalculateRating 作为静态的,不能在非静态字段中引用 mainContext 。

应该使用依赖注入创建计算类的实例。以下是步骤:

1. 创建接口计算

   public interface ICalculateRating { decimal CreateRating(OfferForCreate offer); }

2. 更新计算类以实现icalculaterating

3. 在中注册dbcontext和icalculaterating映射 ConfigureServices startup.cs文件的方法如下:

   services.AddDbContext<DbContext>(opts=> { opts.UseSqlServer("sqlserver conntection string") }, ServiceLifetime.Scoped);

   services.AddTransient<ICalculateRating, CalculateRating>();

4. 在控制器构造函数中,输入icalculaterating类型的参数,该参数将在运行时由Microsoft依赖项注入框架注入:

   private readonly ICalculateRating _calculateRating; public MyController(ICalculateRating calculateRating) { _calculateRating = calculateRating; }

然后您可以这样调用方法: offerForCreate.Rating = _calculateRating.CreateRating(addOffer);