Entity Validation Error

Hello Kumar

the same error still exist

 public partial class tblManufacturer
    {
        public tblManufacturer()
        {
            this.tblItems = new HashSet();
        }
    
        public int ManufactureID { get; set; }
        public string ManufacturerName { get; set; }
        public string Description { get; set; }
    
        public virtual ICollection tblItems { get; set; }
    }

 public partial class tblItem
    {
        public tblItem()
        {
            this.tblPurchaseItems = new HashSet();
            this.tblStocks = new HashSet();
        }
    
        public int ItemID { get; set; }
        public string ItemName { get; set; }
        public Nullable DrugGenericNameID { get; set; }
        public Nullable ManufacturerID { get; set; }
        public Nullable Category { get; set; }
        public Nullable AlertQty { get; set; }
        public string Description { get; set; }
        public Nullable LastUpdated { get; set; }
    
        public virtual ICollection tblPurchaseItems { get; set; }
        public virtual ICollection tblStocks { get; set; }
        public virtual tblManufacturer tblManufacturer { get; set; }
        public virtual tblDrugGenericName tblDrugGenericName { get; set; }
    }

   public partial class tblDrugGenericName
    {
        public tblDrugGenericName()
        {
            this.tblItems = new HashSet();
        }
    
        public int DrugGenericID { get; set; }
        public string DrugGenericName { get; set; }
        public string Description { get; set; }
    
        public virtual ICollection tblItems { get; set; }
    }

Could you please share the below tables? full class, You are missing the configuration for your relationship in EF core

1. Items
2. DrugGenericNames
3. Manufacturer

Hello Kumar

HTML

                                @foreach (var item in Model)
                                {
                                   
                                       
                                            @Html.DisplayFor(modelItem => item.ItemID)
                                       
                                       
                                            @Html.DisplayFor(modelItem => item.ItemName)
                                       
                                       
                                            @Html.DisplayFor(modelItem => item.Manufacturer.ManufacturerName)
                                       
                                       
                                            @Html.DisplayFor(modelItem => item.DrugGenericNames.DrugGenericName)
                                       
                                       
                                            @Html.DisplayFor(modelItem => item.Category)
                                       
                                       
                                            @Html.DisplayFor(modelItem => item.AlertQty)
                                       
                                       
                                            @Html.ActionLink("Edit", "Edit", new { id = item.ItemID }) |
                                            @Html.ActionLink("Details", "Details", new { id = item.ItemID }) |
                                            @Html.ActionLink("Delete", "Delete", new { id = item.ItemID })
                                       
                                   
                                }
                           

CONTROLLER

  public ActionResult Index()
        {
          
            var items = db.Items.Include(i => i.DrugGenericNames).Include(i => i.Manufacturer).OrderByDescending(i => i.ItemID);
            return View(items.ToList());
          
        }

This is the error from the format  you asked me to follow

This is the error that comes from the DbSet

Could you please help here with your error? That will help to identify the root casue. Share the class here in which you are getting error.         

  

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
      modelBuilder.Conventions.Remove();
      modelBuilder.Entity().ToTable("YourSQLTableMappedToClass").HasKey("PrimaryKeyColumnName");

//Do for all table here 

}        

Hello Jignesh Kumar

I crosse checked all my tables and I can say that all of them have primary,

and looking at the screenshot in the above the error is pointing to the DbSet and i tried to remodified it again but the error still exist, any further assistance will be highly appreciated.

public class MyContext : DbContext
    {
        public ASPNETPHARMACYDBEntities db;
        public MyContext()
        {
            db = new ASPNETPHARMACYDBEntities();
        }
        public DbSet DrugGenericNames { get; set; }
        public DbSet Items { get; set; }
        public DbSet Manufacturers { get; set; }
        public DbSet Stocks { get; set; }
        public DbSet Suppliers { get; set; }
        public DbSet Purchases { get; set; }
        public DbSet PurchaseItems { get; set; }
        public DbSet Notifications { get; set; }
        public DbSet SalesReturns { get; set; }
        public DbSet SalesReturnDetails { get; set; }
        public DbSet Sales { get; set; }
        public DbSet SalesItems { get; set; }
       
        public DbSet Users { get; set; }
        //avoids pluralizing table names in database
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Conventions.Remove();
            

        }        
    }

Hello Jignesh Kumar

Please I have apply the [Key] to all the classes but the same error still exist.

you need to check for all your table should follow the same, In your Stock class you are missing key,

public class Stock
{
    public Stock()
    {
        BatchNo = "--";
        Stop_Notification = true;
        ItemExpired = false;
    }
    [Key]
    public int StockID { get; set; }
    [Required]
    public int ItemID { get; set; }

    [StringLength(20, ErrorMessage="Too long. Plese check again!")]
    public string BatchNo { get; set; }

    [Range(0,9999999)]
    public int InitialQty { get; set; }
}

You need to verify the following: If the Id column does not exist, you must designate the primary key using the [Key] annotation.

1. tblNotification
2. tblPurchaseItem
3. tblItem
4. tblDrugGenericNames

Hello Jignesh Kumar,

I have [Key] for the ID in the model as you can see and I didn't know the cause of the error.

 public class DrugGeneric
    {
        [Key]
        public int DrugGenericID { get; set; }      
        [Required]
        [StringLength(50, ErrorMessage="Maximum limit exceeded")]
        public string DrugGenericName { get; set; }
        public string Description { get; set; }

        public virtual ICollection Items { get; set; }

    
    }
}

public class Item
    {
        [Key]
        public int ItemID { get; set; }        
        [Required]
        [Display(Name="Item")]
         public string ItemName { get; set; }
}

  public class Stock
    {
         public Stock()
        {
            BatchNo = "--";
            Stop_Notification = true;
            ItemExpired = false;
        }
         public int StockID { get; set; }
        [Required]
        public int ItemID { get; set; }

        [StringLength(20, ErrorMessage="Too long. Plese check again!")]
        public string BatchNo { get; set; }

        [Range(0,9999999)]
        public int InitialQty { get; set; }
}

Hello,

You need to check primary key for you table, in your case your model name should have Id column other wise you need to mark your primary key column with [Key] attribute as below

public class MyEntity
{
    [Key]
    public int MyEntityId { get; set; }
    
    public string Name { get; set; }
}

else Your all class should follow Id column like below,

public class tblNotification
{
  public int Id { get; set; }
  // other columns here
}

public class tblPurchaseItem
{
  public int Id { get; set; }
  // other columns here
}

If you follow this for all remaining table then your issue will resolve

Thanks