I have a POCO class that implements IComparable
.
public interface IEntity : IComparable
{
long Id { get; set; }
Func<IEntity, bool> CompareFunction { get; }
}
public abstract class BaseEntity : IEntity
{
public virtual long Id { get; set; }
public Func<IEntity, bool> CompareFunction
{
get
{
Func<IEntity, bool> compare = EvaluateEquivalency;
return compare;
}
}
public static int Compare(BaseEntity left, BaseEntity right)
{
if (object.ReferenceEquals(left, right))
{
return 0;
}
if (object.ReferenceEquals(left, null))
{
return -1;
}
return left.CompareTo(right);
}
public static bool operator ==(BaseEntity left, BaseEntity right)
{
if (object.ReferenceEquals(left, null))
{
return object.ReferenceEquals(right, null);
}
return left.Equals(right);
}
public static bool operator !=(BaseEntity left, BaseEntity right)
{
return !(left == right);
}
public static bool operator <(BaseEntity left, BaseEntity right)
{
return Compare(left, right) < 0;
}
public static bool operator >(BaseEntity left, BaseEntity right)
{
return Compare(left, right) > 0;
}
public override bool Equals(object obj)
{
IEntity other;
if (!(obj is IEntity)) return false;
other = (IEntity)obj;
if (object.ReferenceEquals(other, null))
{
return false;
}
return this.CompareTo(other) == 0;
}
public override int GetHashCode()
{
return base.GetHashCode();
}
public virtual int CompareTo(object obj)
{
if (obj == null) throw new ArgumentNullException("obj");
if (!(obj is IEntity)) throw new ArgumentException("obj is not an IEntity");
if (this.Id == ((IEntity)obj).Id) return 0;
return -1;
}
private bool EvaluateEquivalency(IEntity toCompare)
{
return Equals(toCompare);
}
}
There is DbSet
for my POCO class in my DbContext
.
However, when I execute BaseRepository.Exists()
I get a System.NotSupportedException
.
public class BaseRepository<TEntity> : IRepository<TEntity> where TEntity : class, IEntity
{
...
private TEntity Exists(TEntity entity)
{
return Context.DbSet<TEntity>.FirstOrDefult(i => i.CompareTo(entity) == 0);
}
private TEntity ExistsV2(TEntity entity)
{
return Context.DbSet<TEntity>.FirstOrDefult(i => i.CompareFunction(entity) == 0);
}
...
}
The exception stack trace looks like...
System.NotSupportedException was unhandled by user code
Message=Unable to create a constant value of type '{My POCO Class}'. Only primitive types or enumeration types are supported in this context.
Source=System.Data.Entity
StackTrace:
at System.Data.Objects.ELinq.ExpressionConverter.ConstantTranslator.TypedTranslate(ExpressionConverter parent, ConstantExpression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.EqualsTranslator.TypedTranslate(ExpressionConverter parent, BinaryExpression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input, DbExpressionBinding& binding)
at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, DbExpression& source, DbExpressionBinding& sourceBinding, DbExpression& lambda)
at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.FirstPredicateTranslatorBase.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.Convert()
at System.Data.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
at System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
at System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator()
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
at System.Data.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__1[TResult](IEnumerable`1 sequence)
at System.Data.Objects.ELinq.ObjectQueryProvider.ExecuteSingle[TResult](IEnumerable`1 query, Expression queryRoot)
at System.Data.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute[S](Expression expression)
at System.Data.Entity.Internal.Linq.DbQueryProvider.Execute[TResult](Expression expression)
at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source, Expression`1 predicate)
When I execute BaseRepository.ExistsV2()
I get a slightly different System.NotSupportedException
.
System.NotSupportedException was unhandled by user code
HResult=-2146233067
Message=The LINQ expression node type 'Invoke' is not supported in LINQ to Entities.
Source=System.Data.Entity
StackTrace:
at System.Data.Objects.ELinq.ExpressionConverter.NotSupportedTranslator.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateLambda(LambdaExpression lambda, DbExpression input, DbExpressionBinding& binding)
at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.OneLambdaTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, DbExpression& source, DbExpressionBinding& sourceBinding, DbExpression& lambda)
at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.FirstPredicateTranslatorBase.Translate(ExpressionConverter parent, MethodCallExpression call)
at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
at System.Data.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TypedTranslator`1.Translate(ExpressionConverter parent, Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
at System.Data.Objects.ELinq.ExpressionConverter.Convert()
at System.Data.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
at System.Data.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
at System.Data.Objects.ObjectQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator()
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
at System.Data.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__1[TResult](IEnumerable`1 sequence)
at System.Data.Objects.ELinq.ObjectQueryProvider.ExecuteSingle[TResult](IEnumerable`1 query, Expression queryRoot)
at System.Data.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute[S](Expression expression)
at System.Data.Entity.Internal.Linq.DbQueryProvider.Execute[TResult](Expression expression)
at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source, Expression`1 predicate)
I've read the Entity Framework doesn't support IComparable
? Is there anyway around this or does anyone know whether the functionality will be available in EF6?
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