一 背景
今天在使用EntityFrameworkCore 查询的时候在调试的时候总是提示如下错误：Unable to cast object of type ‘System.Data.SqlTypes.SqlString’ to type ‘System.Data.SqlTypes.SqlGuid’ 第一次看这个报错肯定是数据库实体和EFCore中定义的某种类型不匹配从而导致类型转换错误，但是业务涉及到这么多的实体Entity,那么到底是哪里类型无法匹配呢？所以第一步肯定是调试代码，然后看报错信息，这里我们首先贴出完整的报错信息，从而方便自己分析具体问题。
System.InvalidCastException: Unable to cast object of type 'Sys<span>本文来源gaodai#ma#com搞*!代#%^码网5</span>tem.Data.SqlTypes.SqlString' to type 'System.Data.SqlTypes.SqlGuid'. at System.Data.SqlClient.SqlBuffer.get_SqlGuid() at System.Data.SqlClient.SqlDataReader.GetGuid(Int32 i) at lambda_method(Closure , DbDataReader ) at Microsoft.EntityFrameworkCore.Storage.Internal.TypedRelationalValueBufferFactory.Create(DbDataReader dataReader) at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.Enumerator.BufferlessMoveNext(DbContext _, Boolean buffer) at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded) at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.Enumerator.MoveNext() at Microsoft.EntityFrameworkCore.Query.Internal.LinqOperatorProvider._TrackEntities[TOut,TIn](IEnumerable`1 results, QueryContext queryContext, IList`1 entityTrackingInfos, IList`1 entityAccessors)+MoveNext() at Microsoft.EntityFrameworkCore.Query.Internal.LinqOperatorProvider.ExceptionInterceptor`1.EnumeratorExceptionInterceptor.MoveNext() at System.Linq.Lookup`2.CreateForJoin(IEnumerable`1 source, Func`2 keySelector, IEqualityComparer`1 comparer) at System.Linq.Enumerable.JoinIterator[TOuter,TInner,TKey,TResult](IEnumerable`1 outer, IEnumerable`1 inner, Func`2 outerKeySelector, Func`2 innerKeySelector, Func`3 resultSelector, IEqualityComparer`1 comparer)+MoveNext() at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer) at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector) at Sunlight.Dcs.Application.Sales.SalesOrder.DegradedVehicleContracts.DegradedVehicleContractService.QueryByIdAsync(Int32 id) in E:\63318\sales-service\src\sales.orders\Application.Sales.Orders\SalesOrder\DegradedVehicleContracts\DegradedVehicleContractService.cs:line 99 at Abp.Threading.InternalAsyncHelper.AwaitTaskWithPostActionAndFinallyAndGetResult[T](Task`1 actualReturnValue, Func`1 postAction, Action`1 finalAction) at Sunlight.Dcs.WebApi.Sales.Controllers.Orders.DegradedVehicleContractController.QueryById(Int32 id) in E:\63318\sales-service\src\WebApi.Sales\Controllers\Orders\DegradedVehicleContractController.cs:line 50 at Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments) at System.Threading.Tasks.ValueTask`1.get_Result() at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeActionMethodAsync() at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeNextActionFilterAsync() at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context) at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted) at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync() at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextExceptionFilterAsync()
二 解决方案
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转载请注明原文链接：记一次EFCore类型转换错误及解决方案
转载请注明原文链接：记一次EFCore类型转换错误及解决方案
