Q:

ef-code-first one-to-many relation with tinyint primary key migration fails

I am using Entity Framework Code-First and I am new to that. Here are my models:
public class Tbl_Organization_Type
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public byte fld_organization_type_id { get; set; }

    [MaxLength(100)]
    public string fld_organization_type_name { get; set; }

    public byte? fld_sort { get; set; }

    public ICollection<Tbl_Organization> Tbl_Organization { get; set; }

}

public class Tbl_Organization
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public long fld_organization_id { get; set; }
    public long? fld_organization_parent_id_ref { get; set; }

    [StringLength(500)]
    public string fld_organization_name { get; set; }

    [StringLength(200)]
    public string fld_organization_address { get; set; }

    [ForeignKey("fld_location_id_ref")]
    public Tbl_Personnel_Location Tbl_Personnel_Location { get; set; }

    [ForeignKey("fld_organization_type_id_ref")]
    public Tbl_Organization_Type Tbl_Organization_Type { get; set; }
}

When i add ( add-migration personnel_1 -context PersonnelDbContext )
it gives me below error :

The relationship from 'Tbl_Organization.fld_organization_type_id' to
'Tbl_Organization_Type.Tbl_Organization' with foreign key properties
{'fld_organization_type_id_ref' : Nullable} cannot target the
primary key {'fld_organization_type_id' : byte} because it is not
compatible.
Configure a principal key or a set of compatible foreign
key properties for this relationship.

A:

That does not look like a correct model (fld_organization_type_id_ref is not shown or is mistyped). IAC, that field needs to be of the same type as the primary key for Tbl_Organization_Type (byte). Try:
public class Tbl_Organization
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public long fld_organization_id { get; set; }
    public byte? fld_organization_type_id_ref { get; set; }  // This FK needs to match referenced PK type 
    // Are you missing or not showing fld_location_id_ref

    [StringLength(500)]
    public string fld_organization_name { get; set; }

    [StringLength(200)]
    public string fld_organization_address { get; set; }

    [ForeignKey("fld_location_id_ref")]
    public Tbl_Personnel_Location Tbl_Personnel_Location { get; set; }

    [ForeignKey("fld_organization_type_id_ref")]
    public Tbl_Organization_Type Tbl_Organization_Type { get; set; }
}

Similarly, you need to show/define the field fld_location_id_ref and match the type with the reference table Tbl_Personnel_Location.

