将 linq 的方法转换为实体表达式以查询实体框架

Question

I have this problem and I really don't know how to solve it. I asked two questions before abput this problem but didn't get to figure the right answer for my situation. Here is the problem in details. I have an interface and default implementation:

public interface IEntityPriceDefinition
{
    PriceDefinition PriceDefinition { get; }

    bool IsMatch(long additionId);

    bool IsMatch(long? entityId, long? inviterId, long? routeId, long? luggageTypeId);

    bool IsMatch(long? entityId, long? inviterId, long? routeId, long? luggageTypeId,
        long additionId);

    bool IsMatch(long? entityId, Task3 task);

    bool IsMatch(long? entityId, Task3 task, long additionId);
}

public class EntityPriceDefinition : IEntityPriceDefinition
    {
        private PriceDefinition _PriceDefinition;
        private Func<long?, bool> _IsEntityIdMatch;
        private Func<Task3, long?> _TaskValue;

        public PriceDefinition PriceDefinition { get { return _PriceDefinition; } }

        internal EntityPriceDefinition(
            PriceDefinition priceDefinition,
            Func<long?, bool> isEntityIdMatch,
            Func<Task3, long?> taskValue)
        {
            _PriceDefinition = priceDefinition;
            _IsEntityIdMatch = isEntityIdMatch;
            _TaskValue = taskValue;
        }

        public bool IsMatch(long additionId)
        {
            return PriceDefinition.AdditionsPrices.Any(x => x.AdditionId == additionId);
        }

        private bool IsMatch(long? inviterId, long? routeId, long? luggageTypeId)
        {
            bool isMatch = inviterId.HasValue || routeId.HasValue || luggageTypeId.HasValue;
            if (isMatch)
            {
                if (PriceDefinition.InviterId.HasValue && inviterId.HasValue)
                {
                    if (PriceDefinition.InviterId.Value != inviterId.Value) { isMatch = false; }
                }
                if (PriceDefinition.LuggageTypeId.HasValue && luggageTypeId.HasValue)
                {
                    if (PriceDefinition.LuggageTypeId.Value != luggageTypeId.Value) { isMatch = false; }
                }
                if (PriceDefinition.RouteId.HasValue && routeId.HasValue)
                {
                    if (PriceDefinition.RouteId.Value != routeId.Value) { isMatch = false; }
                }
            }
            return isMatch;
        }

        public bool IsMatch(long? entityId, long? inviterId, long? routeId, long? luggageTypeId)
        {
            return _IsEntityIdMatch(entityId) && IsMatch(inviterId, routeId, luggageTypeId);
        }

        public bool IsMatch(long? entityId, long? inviterId, long? routeId, long? luggageTypeId,
            long additionId)
        {
            return IsMatch(entityId, inviterId, routeId, luggageTypeId) && IsMatch(additionId);
        }

        public bool IsMatch(long? entityId, Task3 task)
        {
            bool isMatch = _IsEntityIdMatch(_TaskValue(task)) &&
                IsMatch(task.InviterId, task.RouteId, task.LuggageTypeId);

            for (int i = 0; i < PriceDefinition.Rules.Count && isMatch == true; i++)
            {
                object value = task.GetFieldObjectValue(PriceDefinition.Rules[i].FieldName);
                isMatch = PriceDefinition.Rules[i].IsMatch((value ?? string.Empty).ToString());
            }
            return isMatch;
        }

        public bool IsMatch(long? entityId, Task3 task, long additionId)
        {
            return IsMatch(entityId ,task) && IsMatch(additionId);
        }
    }

I also have 3 classes that implement IEntityPriceDefinition using the default implementation. Here are two of those classes (the third is the same):

public class CustomerPriceDefinition : IEntityPriceDefinition, IDataEntity
    {
        private IEntityPriceDefinition _EntityPriceDefinition;

        public virtual long PriceDefinitionId { get; set; }
        public virtual long CustomerId { get; set; }
        public virtual PriceDefinition PriceDefinition { get; set; }

        public CustomerPriceDefinition()
        {
            _EntityPriceDefinition = new EntityPriceDefinition(
                PriceDefinition,
                entityId => entityId.HasValue && entityId.Value == CustomerId,
                t => t.CustomerId);
        }

        public bool IsMatch(long additionId)
        {
            return _EntityPriceDefinition.IsMatch(additionId);
        }

        public bool IsMatch(long? customerId, long? inviterId, long? routeId, long? luggageTypeId)
        {
            return _EntityPriceDefinition.IsMatch(customerId, inviterId, routeId, luggageTypeId);
        }

        public bool IsMatch(long? customerId, long? inviterId, long? routeId, long? luggageTypeId,
            long additionId)
        {
            return _EntityPriceDefinition.IsMatch(customerId, inviterId, routeId, luggageTypeId,
                additionId);
        }

        public bool IsMatch(long? customerId, Task3 task)
        {
            return _EntityPriceDefinition.IsMatch(customerId, task);
        }

        public bool IsMatch(long? customerId, Task3 task, long additionId)
        {
            return _EntityPriceDefinition.IsMatch(customerId, task, additionId);
        }
    }

public class WorkerPriceDefinition : IEntityPriceDefinition, IDataEntity
    {
        private IEntityPriceDefinition _EntityPriceDefinition;

        public virtual long PriceDefinitionId { get; set; }
        public virtual long WorkerId { get; set; }
        public virtual PriceDefinition PriceDefinition { get; set; }

        public WorkerPriceDefinition()
        {
            _EntityPriceDefinition = new EntityPriceDefinition(
                PriceDefinition,
                entityId => entityId.HasValue && entityId.Value == WorkerId,
                t => t.WorkerId);
        }

        public bool IsMatch(long additionId)
        {
            return _EntityPriceDefinition.IsMatch(additionId);
        }

        public bool IsMatch(long? workerId, long? inviterId, long? routeId, long? luggageTypeId)
        {
            return _EntityPriceDefinition.IsMatch(workerId, inviterId, routeId, luggageTypeId);
        }

        public bool IsMatch(long? workerId, long? inviterId, long? routeId, long? luggageTypeId,
            long additionId)
        {
            return _EntityPriceDefinition.IsMatch(workerId, inviterId, routeId, luggageTypeId,
                additionId);
        }

        public bool IsMatch(long? workerId, Task3 task)
        {
            return _EntityPriceDefinition.IsMatch(workerId, task);
        }

        public bool IsMatch(long? workerId, Task3 task, long additionId)
        {
            return _EntityPriceDefinition.IsMatch(workerId, task, additionId);
        }
    }

I have also repository interface and default implementation for those classes:

public interface IEntityPriceDefinitionRepository<T> : IRepository<T>
    where T : class, IEntityPriceDefinition, IDataEntity
{
    IEnumerable<T> GetMatchPrices(
        Guid companyId, bool? isSuggested, bool? isValid,
        long? entityId, long? inviterId, long? routeId, long? luggageTypeId,
        Func<IQueryable<T>, IOrderedQueryable<T>> orderBy,
        Expression<Func<T, object>>[] includes);

    IEnumerable<T> GetMatchPrices(
        Guid companyId, bool? isSuggested, bool? isValid,
        long? entityId, long? inviterId, long? routeId, long? luggageTypeId, long additionId,
        Func<IQueryable<T>, IOrderedQueryable<T>> orderBy,
        Expression<Func<T, object>>[] includes);
}

public class EntityPriceDefinitionRepository<T> : BaseRepository<T>,
    IEntityPriceDefinitionRepository<T> where T : class,IEntityPriceDefinition, IDataEntity
{
    private IEnumerable<T> GetMatchPrices(
        Guid companyId, bool? isSuggested, bool? isValid,
        Expression<Func<T, bool>> isMatch,
        Func<IQueryable<T>, IOrderedQueryable<T>> orderBy,
        Expression<Func<T, object>>[] includes)
    {
        var filters = new Expression<Func<T, bool>>[]{
            x => x.PriceDefinition.CompanyId == companyId,
            x => x.PriceDefinition.IsDeleted == false,
            x => !isValid.HasValue || x.PriceDefinition.IsValid == isValid.Value,
            x => !isSuggested.HasValue || x.PriceDefinition.IsSuggested == isSuggested.Value,
            isMatch
        };

        return GetQuery(filters, orderBy, includes);
    }

    public IEnumerable<T> GetMatchPrices(
        Guid companyId, bool? isSuggested, bool? isValid,
        long? entityId, long? inviterId, long? routeId, long? luggageTypeId,
        Func<IQueryable<T>, IOrderedQueryable<T>> orderBy,
        Expression<Func<T, object>>[] includes)
    {
        return GetMatchPrices(companyId, isSuggested, isValid,
        //////////////////  THIS CAUSE THE EXCEPTION MENTIONED BELOW:  //////////////////
            x => x.IsMatch(entityId, inviterId, routeId, luggageTypeId),
            orderBy, includes);
    }

    public IEnumerable<T> GetMatchPrices(
        Guid companyId, bool? isSuggested, bool? isValid,
        long? entityId, long? inviterId, long? routeId, long? luggageTypeId, long additionId,
        Func<IQueryable<T>, IOrderedQueryable<T>> orderBy,
        Expression<Func<T, object>>[] includes)
    {
        return GetMatchPrices(companyId, isSuggested, isValid,
        //////////////////  THIS CAUSE THE EXCEPTION MENTIONED BELOW:  //////////////////
            x => x.IsMatch(entityId, inviterId, routeId, luggageTypeId, additionId),
            orderBy, includes);
    }        
}

And the classes repository classes are just:

 public class CustomerPriceDefinitionRepository :
        EntityPriceDefinitionRepository<CustomerPriceDefinition> { }

    public class WorkerPriceDefinitionRepository :
        EntityPriceDefinitionRepository<WorkerPriceDefinition> { }

The problem happend when I call CustomerPriceDefinitionRepository's GetMatchPrices method. It always ends up with exception about the method that marked above:

LINQ to Entities does not recognize the method 'Boolean IsMatch(System.Nullable 1[System.Int64], System.Nullable 1[System.Int64], System.Nullable 1[System.Int64], System.Nullable 1[System.Int64])' method, and this method cannot be translated into a store expression.

Ladislav Mrnka's answered me here to use model defined functions but I want all my code to be in its classes and not in xml's. In addition, this code doesn't relevant to the huge scope that the edmx uses. In addition, I believe that in order to use model defined functions I will have to define 3 methods - one IsMatch for each sub class of IEntityPriceDefinition.

I really don't know how to solve this problem and what is the best solution for such case especially for such non-simple structure. I will appriciate any help.

Answer 1

I added a static method in EntityPriceDefinition:

   public static Expression<Func<CustomerPriceDefinition, bool>> IsMatchExpression(
        long? entityId, long? inviterId, long? routeId, long? luggageTypeId, long additionId)
    {
        return x =>
            (entityId.HasValue && entityId.Value == x.CustomerId) &&
            (inviterId.HasValue || routeId.HasValue || luggageTypeId.HasValue) &&
            !(
                (x.PriceDefinition.InviterId.HasValue && inviterId.HasValue &&
                    x.PriceDefinition.InviterId.Value != inviterId.Value) ||

                (x.PriceDefinition.LuggageTypeId.HasValue && luggageTypeId.HasValue &&
                    x.PriceDefinition.LuggageTypeId.Value != luggageTypeId.Value) ||

                (x.PriceDefinition.InviterId.HasValue && inviterId.HasValue &&
                    x.PriceDefinition.InviterId.Value != inviterId.Value)
            ) &&
            x.PriceDefinition.AdditionsPrices.Any(a => a.AdditionId == additionId);
    }

That way the expression knows how to transform it to query.