Я пытаюсь получить доступ к значению контакта в запросе LINQ через отражение. Я использую.NET С#.
Поэтому у меня есть класс данных, в котором я использую отражение, также получаю значение из свойства, имеющего определенный атрибут ([ConexioSearchField]
).
Пример:
[ConexioSearchField]
public string FullName { get; set; }
Это код, где я делаю это прямо сейчас:
//Starting the Linq Query
var unitOfWork = new SynchronizationUnitOfWork(_context);
var repository = unitOfWork.RepositoryAsync<TC>();
var entities = repository.Queryable();
var firstOrDefault = EntityTypeDescriptorStore.GetEntityTypeDescriptor<TC>().Properties.FirstOrDefault(sf => sf.IsSearchField);
if (firstOrDefault == null) return entities;
var propertyInfo = firstOrDefault.PropertyInfo;
entities = type == HandledType.Doubtful
? entities.Where(entity1 => entity1.IsDoubtful && propertyInfo.GetValue(entity1).ToString().Contains(nameFilter))
: entities.Where(entity1 => propertyInfo.GetValue(entity1).ToString().Contains(nameFilter));
Но это ошибка, которая у меня есть:
Test method Conexio.Core.Orchestration.Test.Doubtfuls.SearchContactsTest.TestSearch3 threw
exception:
System.AggregateException: One or more errors occurred. ---> System.NotSupportedException: LINQ to Entities does not recognize the method 'System.Object GetValue(System.Object)' method, and this method cannot be translated into a store expression.
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.DefaultTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator'1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.StringTranslatorUtil.ConvertToString(ExpressionConverter parent, Expression linqExpression)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.ToStringTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator'1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateFunctionIntoLike(MethodCallExpression call, Boolean insertPercentAtStart, Boolean insertPercentAtEnd, Func'5 defaultTranslator)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.StringContainsTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator'1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input, ref DbExpressionBinding binding)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, ref DbExpression source, ref DbExpressionBinding sourceBinding, ref DbExpression lambda)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator'1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, ref DbExpression source, ref DbExpressionBinding sourceBinding, ref DbExpression lambda)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator'1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.UnarySequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator'1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.UnarySequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator'1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.Convert()
at System.Data.Entity.Core.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable'1 forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery'1.<>c__DisplayClassc.<GetResultsAsync>b__a()
at System.Data.Entity.Core.Objects.ObjectContext.<ExecuteInTransactionAsync>d__3d'1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.<ExecuteAsyncImplementation>d__9'1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Data.Entity.Utilities.TaskExtensions.CultureAwaiter'1.GetResult()
at System.Data.Entity.Core.Objects.ObjectQuery'1.<GetResultsAsync>d__e.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Data.Entity.Utilities.TaskExtensions.CultureAwaiter'1.GetResult()
at System.Data.Entity.Internal.LazyAsyncEnumerator'1.<FirstMoveNextAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Data.Entity.Infrastructure.IDbAsyncEnumerableExtensions.<ForEachAsync>d__5'1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter'1.GetResult()
at Conexio.Core.Orchestration.Contacts.Doubtfuls.SearchDoubtfuls'3.<SearchAsync>d__5.MoveNext() in SearchDoubtfuls.cs: line 59
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter'1.GetResult()
at Conexio.Core.Orchestration.Contacts.ConexioEntityBL'3.<SearchDoubtfulsAsync>d__28.MoveNext() in ConexioEntityBL.cs: line 323
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task'1.GetResultCore(Boolean waitCompletionNotification)
at System.Threading.Tasks.Task'1.get_Result()
at Conexio.Core.Orchestration.Test.Doubtfuls.SearchContactsTest.TestSearch3() in SearchContactsTest.cs: line 77
Расширение D Stanley отвечает на выражение выражения, вот выражение.
var entity1 = Expression.Parameter(typeof(Entity));
var nameFilterExp = Expression.Call(
Expression.Property(entity1, firstOrDefault.PropertyInfo.Name),
typeof(string).GetMethod("Contains", new[] { typeof(string) }),
Expression.Constant(nameFilter)
);
var predicate = Expression.Lambda<Func<Entity, bool>>(
type == HandledType.Doubtful
? (Expression)Expression.AndAlso(Expression.Equal(Expression.Property(entity1, "IsDoubtful"), Expression.Constant(true)), nameFilterExp)
: (Expression)nameFilterExp,
entity1);
entities = entities.Where(predicate);
Проблема в том, что EF пытается превратить ваши ситуации Where
в WHERE
SQL WHERE
и не знает, что делать с вызовами отражения.
Несколько вариантов:
propertyInfo
для генерации Expression
которое EF может перевести на SQL