Geek Answers Handbook

How do you use FirstOrDefault with Include?

This works great:

return Members .FirstOrDefault(m => m.Agreement.Equals(agreement));

But this throws an exception if it does not find a match:

  return Members .Include("Files") .FirstOrDefault(m => m.Agreement.Equals(agreement) && !m.Files.Any(f => f.Status.Equals(12)));

So, how can I get first / default (which may be null) when I use Include?

The exception is:

Unexpected exception when System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.ConstantTranslator.TypedTranslate (ExpressionConverter parent, ConstantExpression linq) in 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.EqualsTranslator.TypedTranslate(ExpressionConverter parent, BinaryExpression linq) at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator 1.Translate (ExpressionConverter parent, Expression linq) in System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression (Expression linq) in System.Data.Entity .Core.Objects.ELinq.ExpressionConverter.TranslateLambda (LambdaExpression lambda, DbExpression) on System.Data.Entity.Core.Objects.ELinq.ExpressionConverter .TranslateLambda (LambdaExpression lambda, DbExpression input, DbExpressionBinding & binding) with System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate (ExpressionConverter parent, call DoubtBionExpression & DutyBrainExpressionBionExpress lambda) in System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate (ExpressionConverter parent call MethodCallExpression parent, call MethodCallExpression, sequence SequenceMethodMethod)
in System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate (ExpressionConverter parent, MethodCallExpression linq) in 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.NotTranslator.TypedTranslate(ExpressionConverter parent, UnaryExpression linq) at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TypedTranslator 1.Translate (ExpressionConverter parent, Expression linq) in System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression (Expression linq) in System.Data.Entity.Core .Objects.ELinq.ExpressionConverter.BinaryTranslator.TypedTranslate (ExpressionConverter parent, BinaryExpression linq) in 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, DbExpressionBinding& binding) at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, DbExpression& source, DbExpressionBinding& sourceBinding, 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.TranslateLambda(LambdaExpression lambda, DbExpression input) at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input, DbExpressionBinding& binding) at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, DbExpression& source, DbExpressionBinding& sourceBinding, 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.TranslateLambda(LambdaExpression lambda, DbExpression input) at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input, DbExpressionBinding& binding) at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, DbExpression& source, DbExpressionBinding& sourceBinding, 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.Tionlate ) in System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression (Expression linq) in System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.AggregateTranslator.Translate (ExpressionConverter) parent method. Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate (ExpressionConverter parent, call MethodCallExpression, sequence SequenceMethodMethod)
in System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate (ExpressionConverter parent, MethodCallExpression linq) in 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.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.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) with System.Data.Entity.Core.Objects.ObjectQuery 1.<>c__DisplayClass7.<GetResults>b__6() at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func 1 func, IDbExecutionStrategy executeStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) in System.Data.Entity.Core.Objects.ObjectQuery <1> .Core.Objects.ObjectQuery 1.GetResults(Nullable 1 forMergeOption) with System.Data.Entity.Core.Objects.ObjectQuery 1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0() at System.Data.Entity.Internal.LazyEnumerator 1.MoveNext () in System.Linq.Enumerable.Single [TSource] (IEnumerable 1 source) at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__3[TResult](IEnumerable 1 sequence) in System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.E xecuteSingle [TResult] (IEnumerable 1 query, Expression queryRoot) at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute[TResult](Expression expression) at System.Data.Entity.Internal.Linq.DbQueryProvider.Execute[TResult](Expression expression) at System.Linq.Queryable.Count[TSource](IQueryable 1 source)

+6
source share
2 answers

How about this:

 return Members .Include("Files") .Where(m => m.Agreement.Equals(agreement) && m.Files != null && !m.Files.Any(f => f.Status.Equals(12))) .FirstOrDefault();
+6
source

try as follows:

 return Members.Include("Files") .FirstOrDefault(m => m.Agreement.Equals(agreement) && !m.Files.Any(f => f.Status==12));

I think this will help you.

0
source

More articles:


All Articles