指定的列数必须与主键列EF的数目匹配

Question

I have two tables having composite pk's. The pk of TABLE1 goes into TABLE2 and they have a one to one optional relationship ie TABLE1 may have 1 TABLE2 or 0 TABLE2. I get the following exception on model creation when I insert data.

The specified association foreign key columns 'third_table_id, fourth_table_id' are invalid. The number of columns specified must match the number of primary key columns.

Any help would be appreciated. The pk's of the table 1 come from table 3

I have defined the mapping TABLE1 as: #region PROPERTIES

        Property(p => p.THIRDTABLEID).HasColumnName("third_table_id").HasDatabaseGeneratedOption(DatabaseGeneratedOption.None).IsRequired();
        Property(p => p.FOURTHTABLEID).HasColumnName("fourth_table_id").HasDatabaseGeneratedOption(DatabaseGeneratedOption.None).IsRequired();

        Property(p => p.SEQID).HasColumnName("Seq_ID").HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity).IsRequired();

        #endregion PROEPRTIES

        #region IGNORE

        Ignore(p => p.RowState);


        #endregion IGNORE

        #region IGNORE

        ToTable("dbo.TABLE1");

        #endregion IGNORE

        #region KEYS
      //  HasKey(t => new { t.THIRDTABLEID, t.FOURTHTABLEID });
        HasKey(t => t.THIRDTABLEID);
        HasKey(t => t.FOURTHTABLEID);

        #endregion KEYS

        #region RELATIONSHIPS

        //relationship
        HasRequired(t => t.THIRDTABLEID).WithMany(c => c.TABLE1).HasForeignKey
                (t => t.THIRDTABLEID).WillCascadeOnDelete(false);

        //relationship
        HasRequired(t => t.SESN).WithMany(c => c.TABLE1).HasForeignKey
                (t => t.SESSIONID).WillCascadeOnDelete(false);

        #endregion RELATIONSHIPS

and the other TABLE2 as:

        #region PROPERTIES

        Property(p => p.BPROLEDETLID).HasColumnName("bp_role_detl_id").HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity).IsRequired();
        Property(p => p.THIRDTABLEID).HasColumnName("third_table_id").HasDatabaseGeneratedOption(DatabaseGeneratedOption.None).IsRequired(); 
        Property(p => p.FOURTHTABLEID).HasColumnName("fourth_table_id").HasDatabaseGeneratedOption(DatabaseGeneratedOption.None).IsRequired(); ;
        Property(p => p.abc).HasColumnName("abc").IsOptional();


        #endregion PROPERTIES

        #region IGNORE

        Ignore(p => p.RowState);

        #endregion IGNORE

        #region TABLE MAPPING

        ToTable("dbo.TABLE2");

        #endregion 

        #region KEYS

      HasKey(t => new {t.THIRDTABLEID, t.FOURTHTABLEID});
        //HasKey(t => t.THIRDTABLEID);
        //HasKey(t => t.FOURTHTABLEID);

        #endregion KEYS

        #region RELATIONSHIPS

        //relationship

        HasRequired(t => t.TABLE1).WithOptional(c => c.TABLE1_DETL).Map(
            m=> m.MapKey(

                "third_table_id",
                "fourth_table_id"

                )).WillCascadeOnDelete(false);



        #endregion RELATIONSHIPS

Answer 1

Your first table is using HasKey twice, instead of creating a composite key. The second statement is just going to override the first one, so it looks like Table 1 has a single primary key, while Table 2 has a composite key of two columns. That's why it's telling you the number of columns must match.