Question

我正在使用ASP.NET Web API 2和Entity Framework开发Web API来访问数据库。我调用我的SQL Server存储过程非常简单，应按如下方式返回一列：

SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE [dbo].[getnationalities]
AS
BEGIN
    SET NOCOUNT ON;  

    SELECT  DISTINCT 
        Table_Price.Price_Nationality AS 'name'
    FROM 
        Table_Price;
END

这是我的vb代码：

Namespace Controllers
    Public Class NationalityController
    Inherits ApiController


    Public Function getcountries() As IHttpActionResult
        Using entities As IAPD_DBEntities = New IAPD_DBEntities()
            Return Ok(entities.getnationalities.ToList)
        End Using
    End Function
End Class
End Namespace

这是我从邮递员那里得到的错误

{ 
    "message": "An error has occurred.",  
    "exceptionMessage": "The data reader is incompatible with the specified 'IAPD_DBModel.Table_Price'. A member of the type, 'Price_PK_ID', does not have a 
corresponding column in the data reader with the same name.",  
"exceptionType": "System.Data.Entity.Core.EntityCommandExecutionException",  
"stackTrace": "   at System.Data.Entity.Core.Query.InternalTrees.ColumnMapFactory.GetMemberOrdinalFromReader(DbDataReader storeDataReader, EdmMember member, EdmType currentType, Dictionary`2 renameList)\r\n   at System.Data.Entity.Core.Query.InternalTrees.ColumnMapFactory.GetColumnMapsForType(DbDataReader storeDataReader, EdmType edmType, Dictionary`2 renameList)\r\n   at System.Data.Entity.Core.Query.InternalTrees.ColumnMapFactory.CreateColumnMapFromReaderAndType(DbDataReader storeDataReader, EdmType edmType, EntitySet entitySet, Dictionary`2 renameList)\r\n   at System.Data.Entity.Core.Query.InternalTrees.ColumnMapFactory.CreateFunctionImportStructuralTypeColumnMap(DbDataReader storeDataReader, FunctionImportMappingNonComposable mapping, Int32 resultSetIndex, EntitySet entitySet, StructuralType baseStructuralType)\r\n   at System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.FunctionColumnMapGenerator.System.Data.Entity.Core.EntityClient.Internal.EntityCommandDefinition.IColumnMapGenerator.CreateColumnMap(DbDataReader reader)\r\n   at System.Data.Entity.Core.Objects.ObjectContext.MaterializedDataRecord[TElement](EntityCommand entityCommand, DbDataReader storeReader, Int32 resultSetIndex, ReadOnlyCollection`1 entitySets, EdmType[] edmTypes, ShaperFactory`1 shaperFactory, MergeOption mergeOption, Boolean streaming)\r\n   at System.Data.Entity.Core.Objects.ObjectContext.CreateFunctionObjectResult[TElement](EntityCommand entityCommand, ReadOnlyCollection`1 entitySets, EdmType[] edmTypes, ExecutionOptions executionOptions)\r\n   at System.Data.Entity.Core.Objects.ObjectContext.<>c__DisplayClass47`1.<ExecuteFunction>b__46()\r\n   at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)\r\n   at System.Data.Entity.Core.Objects.ObjectContext.<>c__DisplayClass47`1.<ExecuteFunction>b__45()\r\n   at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)\r\n   at System.Data.Entity.Core.Objects.ObjectContext.ExecuteFunction[TElement](String functionName, ExecutionOptions executionOptions, ObjectParameter[] parameters)\r\n   at ProjectDataAccess.IAPD_DBEntities.getnationalities() in C:\\Users\\Junaida\\documents\\visual studio 2015\\Projects\\WebApplication7\\ProjectDataAccess\\DataAccessModel.Context.vb:line 5552\r\n   at WebApplication7.Controllers.NationalityController.getcountries() in C:\\Users\\Junaida\\documents\\visual studio 2015\\Projects\\WebApplication7\\WebApplication7\\Controllers\\NationalityController.vb:line 13\r\n   at lambda_method(Closure , Object , Object[] )\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)\r\n   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Controllers.AuthenticationFilterResult.<ExecuteAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"
}

我真正的目标是获得一个数据集或一系列国籍

Answer 1

抱歉，我不知道实体框架，但我可以从存储过程中获取数据列表。

Dim lstNationalities As New List(Of String)
        Using cn As New SqlClient.SqlConnection("Your connection string")
            Using cmd As New SqlClient.SqlCommand With {
                .Connection = cn,
                .CommandType = CommandType.StoredProcedure,
                .CommandText = "getnationalities"}
                cn.Open
                Using dr As SqlClient.SqlDataReader = cmd.ExecuteReader
                    Do While dr.Read
                        lstNationalities.Add(dr.GetString(0))
                    Loop
                End Using
            End Using
        End Using

数据读取器与指定的'IAPD_DBModel.Table_Price不兼容

1 个答案: