如何首先使用流畅的api代码创建循环引用

Question

I need to create a many to many circular relation with two objects in fluent api. And I don't know how to use fluent api to achieve that goal.

The relation should be one to many (required) and one to many (optionnel) I tried this scenario and it's not working.

Here my class model:

[Table("Question")]
    public class Question
    {
        public int ID { get; set; }
        public int IDQuestion { get; set; }
        public int IDForm { get; set; }
        public virtual AnswerSelectionType AssociateAnswerSelectionType { get; set; }
        public virtual ICollection<AnswerSelectionType> AnswerSelectionTypes { get; set; }
    }

    [Table("AnswerSelectionType")]
    public class AnswerSelectionType
    {
        public int ID { get; set; }
        public int IDQuestionForm { get; set; }
        public int? IDAssociateQuestion { get; set; }
        public int? DataValue { get; set; }

        public virtual Question AssociateQuestion { get; set; }
        public virtual Question QuestionForm { get; set; }
    }

After that, here the fluent API

modelBuilder.Entity<AnswerSelectionType>()
        .HasRequired(choixRep => choixRep.QuestionForm)
        .WithMany(questionTe => questionTe.AnswerSelectionTypes)
        .HasForeignKey(fk => fk.IDQuestionForm);

    modelBuilder.Entity<AnswerSelectionType>()
       .HasOptional(choixRep => choixRep.AssociateQuestion)
       .WithMany(many => many.AnswerSelectionTypes)
       .HasForeignKey(fk => fk.IDAssociateQuestion);

The error I got is: The navigation property declared on type has been configured with conflicting multiplicities.

Could you help me to find why I got the error?

Thank you very much!!

Answer 1

AnswerSelectionType would need to have a collection of the entity on the many side. I don't see any collection in AnswerSelectionType .

But I'm not sure what you mean by circular. What is the structure you have in mind?

Question --> 1:n --> AnswerSelectionType --> 1:n -->  Question

In this case a property in AnswerSelectionType would help.

ICollection<Question> Questions { get; set; }

And then

.WithMany(many => many.Questions)

Answer 2

(Note, remove "NHEntity" from the text below)

Try this:

    public class AnswerSelectionTypeNHEntityMapping : ClassMap<AnswerSelectionTypeNHEntity>
    {

        public AnswerSelectionTypeNHEntityMapping()
        {

            Schema("dbo");
            Table("AnswerSelectionTypeNHEntity");

            Id(x => x.AnswerSelectionTypeNHEntityKey).GeneratedBy.Increment();

            Map(x => x.IDQuestionForm);
            Map(x => x.IDAssociateQuestion).Not.Nullable();
            Map(x => x.DataValue).Not.Nullable();

            References<QuestionNHEntity>(x => x.QuestionForm)
                .Class(typeof(QuestionNHEntity))
                /*.Not.Nullable() */
                 .Nullable()
                .Column("ParentQuestionFormKey")
                .Index("IX_AnswerSelectionType_ParentQuestionFormKey")
                .Cascade.SaveUpdate()
                ;


            References<QuestionNHEntity>(x => x.AssociateQuestion )
                .Class(typeof(QuestionNHEntity))
                /*.Not.Nullable() */
                 .Nullable()
                .Column("OneToOneAssociateQuestionKey")
                .Index("IX_AnswerSelectionType_OneToOneAssociateQuestionKeyy")
                .Cascade.SaveUpdate()
                ;


        }


    }


   public class QuestionNHEntityMapping : ClassMap<QuestionNHEntity>
    {

        public QuestionNHEntityMapping()
        {

            Schema("dbo");
            Table("QuestionNHEntity");

            Id(x => x.QuestionNHEntityKey).GeneratedBy.Assigned();

            Map(x => x.IDQuestion).Not.Nullable().Index("IX_Question_IDQuestion"); ;
            Map(x => x.IDForm).Not.Nullable();



            HasMany<AnswerSelectionTypeNHEntity>(x => x.AnswerSelectionTypes)
                .Inverse()
                .KeyColumns.Add("MyAnswerSelectionTypesColumnName")
                ;


            References<AnswerSelectionTypeNHEntity>(x => x.AssociateAnswerSelectionType)
                .Class(typeof(AnswerSelectionTypeNHEntity))
                /*.Not.Nullable() */
                 .Nullable()
                .Column("OneToOneAnswerSelectionTypeNHEntityKey")
                .Index("IX_AnswerSelectionType_OneToOneAnswerSelectionTypeNHEntityKey")
                .Cascade.SaveUpdate()
                ;



        }
    }