Question

I got a table with these columns:

• PdfManuals:
• Id (PK, int, not null)
• Name (nvarchar(150), not null)
• ManufacturerId (int, not null)
• ClientId (nvarchar(50), not null)
• LanguageId (int, not null)
• ImageSize (nvarchar(50), not null)
• PdfName (nvarchar(150), not null)
• Image (image, null)
• Pdf (image, null)

And another table: PdfManuals_Manufacturers

1. Id (PK, int, not null)
2. Name (nvarchar(150), not null)
3. ClientId (nvarchar(50), not null)
4. LanguageId (int, not null)

And trying to perform this action:

public ActionResult DeleteManufacturer(int id)
    {
        var manufacturer = _db.PdfManuals_Manufacturers.Where(x => x.Id == id).SingleOrDefault();
        var pdfManuals = _db.PdfManuals.Where(x => x.ManufacturerId == id).ToList();

        if (manufacturer != null)
        {
            _db.PdfManuals_Manufacturers.DeleteOnSubmit(manufacturer);
            _db.PdfManuals.DeleteAllOnSubmit(pdfManuals);
        }
        _db.SubmitChanges();

        return RedirectToAction("Manufacturers");
    }

But i get this error:

The data types image and varbinary(max) are incompatible in the equal to operator.

I am using ASP.NET MVC, and LINQ-To-SQL
I don’t understand why, maybe you guys can help me? 🙂

Answer 1

This is probably caused by LINQ: it checks for the real change of the value (not always possibile as you can see…).

You can avoid this check with the clause UpdateCheck=UpdateCheck.Never:

[Column(Storage="_myColumn", DbType="VarBinary", UpdateCheck=UpdateCheck.Never)]
public string myColumn
{
...
}

in the LINQ mapping of the column