Cycles or multiple cascade paths

Question

I have the following datamodel and its associated model classes. I have been removing dependencies to get it right, but I keep on getting this error.

Datamodel

I can't find out why there is a cascading path in the model. I am afraid I will not be able to reduce the dependencies.

Model Classes

public class DataFormat
{
    public int DataFormatID { get; set; }
    [Display (Name = "Data Format Name")]
    [Remote("DuplicateFormatName", "DataFormats", HttpMethod = "POST", ErrorMessage = "Data Format Name already Exists")]
    public string FormatName { get; set; }
    [Display (Name = "Data Format Type")]
    public string FormatType { get; set; }
    [Display (Name = "Precision Digits")]
    public string PrecisionDigits { get; set; }
    [Display (Name = "Scaling Digits")]
    public string ScalingDigits { get; set; }
    [Display (Name = "Description in German")]
    public string DescriptionDE { get; set; }
    [Display (Name = "Description in English")]
    public string DescriptionEN { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    public string CreatedBy { get; set;}
    public string ModifiedBy { get; set; }

    public virtual ICollection<TcSet> TcSets { get; set; }
}

public class Lsystem
{
    public int LsystemID { get; set; }
    [Display (Name = "System Name") ]
    [Remote("DuplicateSystemName", "Lsystems", HttpMethod = "POST", ErrorMessage = "System Name already Exists")]
    public string LsystemName { get; set; }
    [Display (Name = "Material Number")]
    public string MaterialNumber { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    public string CreatedBy { get; set; }
    public string ModifiedBy { get; set; }
    [Display(Name = "Description in English")]
    public string DescriptionEN { get; set; }
    [Display(Name = "Description in German")]
    public string DescriptionDE { get; set; }

    public int LsystemFamilyID { get; set; }

    public virtual LsystemFamily LsystemFamily { get; set; }
    public virtual ICollection<Option> Options { get; set; }
}

public class LsystemFamily
{
    public int LsystemFamilyID { get; set; }
    [Display (Name = "Family Name")]
    [Remote("DuplicateFamilyName","LsystemFamilies",HttpMethod = "POST",ErrorMessage= "System Family Name already Exists")]
    public string FamilyName { get; set; }
    public int LsystemCount { get; set; }
    [Display ( Name = "Description in English")]
    public string DescriptionEN { get; set; }
    [Display (Name = "Description in German")]
    public string DescriptionDE { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    public string CreatedBy { get; set; }
    public string ModifiedBy { get; set; }

    public virtual ICollection<Lsystem> Lsystems { get; set; }
}

public class Option
{
    public int OptionID { get; set;}
    [Display (Name = "Option Type")]
    public string OptionName { get; set; }
    [Display (Name ="Description in English")]
    public string DescriptionEN { get; set; }
    [Display(Name = "Description in German")]
    public string DescriptionDE { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    public string CreatedBy { get; set; }
    public string ModifiedBy { get; set; }

    public int TechnicalCharacteristicID { get; set; }
    public int LsystemID { get; set; }

    public virtual ICollection<OptionValue> OptionValues { get; set; }
    public virtual TechnicalCharacteristic TechnicalCharacteristic { get; set; }
    public virtual Lsystem Lsystem { get; set; }
   // public virtual ICollection< SetValue> SetValue { get; set; }
}

public class OptionValue
{
    public int OptionValueID { get; set; }
    [Display(Name = "Option Value")]
    public string OptionVal { get; set; }

    public int OptionID { get; set; }
   // public int SetValueID { get; set; }

    public virtual Option Option { get; set; }
    public virtual ICollection< SetValue> SetValue { get; set; }
}

public class SetValue
{
    public int SetValueID { get; set; }
    [Display(Name = "Value")]
    public string Value { get; set; }
    [Display(Name="Internal")]
    public bool Status { get; set; }

    //public int LsystemID { get; set; }
    //public int OptionID { get; set; }
    public int TcSetID { get; set; }
    public int OptionValueID { get; set; }

    //public virtual Lsystem Lsystem { get; set; }
    //public virtual Option Option { get; set; }
    public virtual OptionValue OptionValue { get; set; }
    public virtual TcSet TcSet { get; set; }

}

public class TcSet
{
    public int TcSetID { get; set; }
    [Display (Name = "Technical characteristic Property name")]
    public string SetName { get; set; }
    [Display(Name = "PhysicalUnit")]
    public string PhysicalUnit { get; set; }
    [Display (Name = "Data Usage")]
    public DataUsage DataUsage { get; set; }
    [Display (Name = "Data Status")]
    public DataStatus DataStatus { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    [Display (Name = "Description in German")]
    public string DescriptionDE { get; set; }
    [Display (Name = "Description in English")]
    public string DescriptionEN { get; set; }
    public string CreatedBy { get; set; }
    public string ModifiedBy { get; set; }

    public int TechnicalCharacteristicID { get; set; }
    public int DataFormatID { get; set; }

    public virtual ICollection<SetValue> SetValues { get; set; }
    public virtual DataFormat DataFormat { get; set; }
    public virtual TechnicalCharacteristic TechnicalCharacteristic { get; set; }
}

public class TechnicalCharacteristic
{
    public int TechnicalCharacteristicID { get; set; }
    [Display (Name = "Technical Characteristic Name")]
    public string TCName { get; set; }
    [Display (Name = "Description in English")]
    public string DescriptionEN { get; set; }
    [Display (Name = "Description in German")]
    public string DescriptionDE { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    public string CreatedBy { get; set; }
    public string ModifiedBy { get; set; }

    public virtual ICollection<TcSet> TcSets { get; set; }
    //public virtual ICollection<Option> Options { get; set; }
}

Now my error is between the tables Options and technicalCharacteristics. I had the error previosly with LSystem and SetVal & Options.

What can be the workaround to get the task right? I have not tried fluent APIs.

Answer 1

Here is another way you can do the same AND have a technicalChareristic to be required. I did this last week with one of my own models. Sorry it toook so long to come up with a reply. (Do the same with the other files.)

In your Context file override the following method...

  protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Option>()
            .HasRequired(x => x.TechnicalCharacteristic)
            .WithMany(y => y.Options)
            .HasForeignKey(a => a.TechnicalCharacteristicID)
            .WillCascadeOnDelete(false);

        base.OnModelCreating(modelBuilder);
    }

Where the models are...

public class Option
{
    public int OptionID { get; set; }
    [Display(Name = "Option Type")]
    public string OptionName { get; set; }
    [Display(Name = "Description in English")]
    public string DescriptionEN { get; set; }
    [Display(Name = "Description in German")]
    public string DescriptionDE { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    public string CreatedBy { get; set; }
    public string ModifiedBy { get; set; }

    public int LsystemID { get; set; }

    public virtual ICollection<OptionValue> OptionValues { get; set; }

    public int TechnicalCharacteristicID { get; set; }
    public virtual TechnicalCharacteristic TechnicalCharacteristic { get; set; }
    public virtual Lsystem Lsystem { get; set; }
    // public virtual ICollection< SetValue> SetValue { get; set; }

    DateTime d = new DateTime();
}


public class TechnicalCharacteristic
{
    public int TechnicalCharacteristicID { get; set; }
    [Display(Name = "Technical Characteristic Name")]
    public string TCName { get; set; }
    [Display(Name = "Description in English")]
    public string DescriptionEN { get; set; }
    [Display(Name = "Description in German")]
    public string DescriptionDE { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    public string CreatedBy { get; set; }
    public string ModifiedBy { get; set; }

    public virtual ICollection<TcSet> TcSets { get; set; }
    public virtual ICollection<Option> Options { get; set; }

}

I hope this helps.

Answer 2

I believe your error is coming because EntityFramework cannot handle the null state of your TechnicalCharacteristicID in the Option class. If you have no problem in TechnicalCharacteristic being null, do the following in your option class. It should get rid of your error:

        public int? TechnicalCharacteristicID { get; set; }

that is, your option class will become...

public class Option
{
    public int OptionID { get; set; }
    [Display(Name = "Option Type")]
    public string OptionName { get; set; }
    [Display(Name = "Description in English")]
    public string DescriptionEN { get; set; }
    [Display(Name = "Description in German")]
    public string DescriptionDE { get; set; }
    public DateTime CreatedOn { get; set; }
    public DateTime ModifiedOn { get; set; }
    public string CreatedBy { get; set; }
    public string ModifiedBy { get; set; }

    public int LsystemID { get; set; }

    public virtual ICollection<OptionValue> OptionValues { get; set; }

    public int? TechnicalCharacteristicID { get; set; }
    public virtual TechnicalCharacteristic TechnicalCharacteristic { get; set; }
    public virtual Lsystem Lsystem { get; set; }
    // public virtual ICollection< SetValue> SetValue { get; set; }
}

Do the same with other errant tables. I hope this answers your question! Good luck.