ขอความช่วยเหลือ เรื่องการ validate ที่ต่างกัน แต่ต้องเรียก db ตัวเดียวกัน asp,net mvc ครับ

namespace WebPrinter.Models
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.Linq;
    using System.Web.Mvc;
    
    public class Owner
    {
        public int id { get; set; }

        [Required]
        [Display(Name="ชื่อ")]
        public string firstname { get; set; }

        [Required]
        [Display(Name="นามสกุล")]
        public string lastname { get; set; }

        public Nullable<System.DateTime> createrdate { get; set; }

        public string username { get; set; }

        [DataType(DataType.Password)]
        public string password { get; set; }

        [Display(Name="Role")]
        public string roles { get; set; }

        [Display(Name="อีเมลล์")]
        public string email { get; set; }

        [Display(Name="ชื่อ - นามสกุล")]
        public string name { get; set; }

        public string HiddenPostBack { get; set; }

        public IEnumerable<Owner> GetActiveMembers
        {
            get
            {
                PrinterStockEntities db = new PrinterStockEntities();
                return (from x in db.Owners
                       select x).ToList();
            }
        }

        public SelectList dp 
        {
            get{
                return new SelectList(new[]{ 
                    new{ ID = "", Name = "-- เลือก Role --"},
                    new{ ID = "Admin", Name = "Admin"},
                    new{ ID = "User", Name = "User"},
                    },
                    "ID", "Name", this.roles);
                }
         }    
    }

    public class LogOnModel
    {
        public int id { get; set; }

        [Required]
        public string username { get; set; }

        [Required]
        [DataType(DataType.Password)]
        public string password { get; set; }
    }

    public class EditUserModel
    {
        public int id { get; set; }

        [Required]
        [Display(Name = "ชื่อ")]
        public string firstname { get; set; }

        [Required]
        [Display(Name = "นามสกุล")]
        public string lastname { get; set; }

        [Required]
        [Display(Name = "Role")]
        public string roles { get; set; }

        [Display(Name = "อีเมลล์")]
        public string email { get; set; }
    }

    public class CreateUserModel
    {
        public int id { get; set; }

        [Required]
        [Display(Name = "ชื่อ")]
        public string firstname { get; set; }

        [Required]
        [Display(Name = "นามสกุล")]
        public string lastname { get; set; }

        [Required]
        [Display(Name = "Role")]
        public string roles { get; set; }

        [Display(Name = "อีเมลล์")]
        public string email { get; set; }

        [Required]
        public string username { get; set; }

        [Required]
        [DataType(DataType.Password)]
        public string password { get; set; }
    }
}

[HttpPost]
        [Authorize(Roles = "Admin")]
        public JsonResult Edit(EditUserModel owner)
        {
            if (ModelState.IsValid)
            {
                System.Diagnostics.Debug.WriteLine("xxx");
                PrinterStockEntities db = new PrinterStockEntities();
                db.Entry(owner).State = EntityState.Modified;
                db.SaveChanges();
               
            }
            else
            {
                string errors = "";
                foreach (ModelState modelState in ViewData.ModelState.Values)
                {
                    foreach (ModelError error in modelState.Errors)
                    {
                        errors += error.ErrorMessage;
                        System.Diagnostics.Debug.WriteLine(error.ErrorMessage);
                    }
                }
            }
            return Json("xxx");
        }

namespace WebPrinter.Models
{
    using System;
    using System.Data.Entity;
    using System.Data.Entity.Infrastructure;
    
    public partial class PrinterStockEntities : DbContext
    {
        public PrinterStockEntities()
            : base("name=PrinterStockEntities")
        {
        }
    
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            throw new UnintentionalCodeFirstException();
        }
    
        public virtual DbSet<ColorUnit> ColorUnits { get; set; }
        public virtual DbSet<Customer> Customers { get; set; }
        public virtual DbSet<DetailDataPrinter> DetailDataPrinters { get; set; }
        public virtual DbSet<Finishing> Finishings { get; set; }
        public virtual DbSet<HeadDataPrinter> HeadDataPrinters { get; set; }
        public virtual DbSet<Machine_Printer> Machine_Printer { get; set; }
        public virtual DbSet<Owner> Owners { get; set; }
        public virtual DbSet<Stock_Paper> Stock_Paper { get; set; }
        public virtual DbSet<Sys_Print> Sys_Print { get; set; }
        public virtual DbSet<Type_Finishing> Type_Finishing { get; set; }
        public virtual DbSet<Unit> Units { get; set; }
        public virtual DbSet<Job_Type> Job_Type { get; set; }
        public virtual DbSet<Transfer> Transfers { get; set; }
        public virtual DbSet<Province> Provinces { get; set; }
    }
}