Hai im new in c# i have doubt with my code. Actually what im trying to do here is when i upload an attachment on my screen level, so this function will save it in my DB table. But what happen now is i dont know which value coming as nvarchar.

This is my C# code

 public ActionResult SaveFile(HttpPostedFileBase file, int senderId, int pictureNumber, DocumentUpload docUpload)
        {
            if (file != null && file.ContentLength > 0)
            {
                byte[] fileData;
                using (var binaryReader = new BinaryReader(file.InputStream))
                {
                    fileData = binaryReader.ReadBytes(file.ContentLength);
                }

                switch (pictureNumber)
                {
                    case 1:
                        docUpload.Picture1 = fileData;
                        break;
                    case 2:
                        docUpload.Picture2 = fileData;
                        break;
                    case 3:
                        docUpload.Picture3 = fileData;
                        break;
                    case 4:
                        docUpload.Picture4 = fileData;
                        break;
                    case 5:
                        docUpload.Picture5 = fileData;
                        break;
            
                }

                var result = _storedProcedureService.GetWithRawSql<int>(
                    "exec sp_UpdateDocumentUpload @p0, @p1, @p2, @p3, @p4, @p5, @p6, @p7",
                    senderId,
                    docUpload.Picture1 ?? (object)DBNull.Value,
                    docUpload.Picture2 ?? (object)DBNull.Value,
                    docUpload.Picture3 ?? (object)DBNull.Value,
                    docUpload.Picture4 ?? (object)DBNull.Value,
                    docUpload.Picture5 ?? (object)DBNull.Value,
                    Convert.ToInt32(Session["EntityId"]),
                    DateTime.Now
                );

                return Json(new { success = true });
            }

            return Json(new { success = false, message = "No file provided" });
        }

And this is my store procedure

ALTER PROCEDURE [dbo].[sp_UpdateDocumentUpload]
   @SenderId INT,
    @Picture1 VARBINARY(MAX) = NULL,
    @Picture2 VARBINARY(MAX) = NULL,
    @Picture3 VARBINARY(MAX) = NULL,
    @Picture4 VARBINARY(MAX) = NULL,
    @Picture5 VARBINARY(MAX) = NULL,
    @CreatedBy INT = null,
    @CreationDate DATETIME = null
AS
BEGIN
    SET NOCOUNT ON;

    IF EXISTS (SELECT * FROM DocumentUpload WHERE SenderId = @SenderId)
    BEGIN
        UPDATE DocumentUpload
        SET 
            Picture1 = COALESCE(@Picture1, Picture1),  
            Picture2 = COALESCE(@Picture2, Picture2),  
            Picture3 = COALESCE(@Picture3, Picture3),  
            Picture4 = COALESCE(@Picture4, Picture4),  
            Picture5 = COALESCE(@Picture5, Picture5),  
            CreatedBy = @CreatedBy,                    
            CreationDate = @CreationDate              
        WHERE SenderId = @SenderId;
    END
    ELSE
    BEGIN
        INSERT INTO DocumentUpload (SenderId, Picture1, Picture2, Picture3, Picture4, Picture5, CreatedBy, CreationDate)
        VALUES (@SenderId, @Picture1, @Picture2, @Picture3, @Picture4, @Picture5, @CreatedBy, @CreationDate);
    END
END

In my module also i did the same datatype

public class DocumentUpload : Entity
    
    {
        public int SenderId { get; set; }
        public byte[] Picture1 { get; set; }
        public byte[] Picture2 { get; set; }
        public byte[] Picture3 { get; set; }
        public byte[] Picture4 { get; set; }
        public byte[] Picture5 { get; set; }
        public Nullable<int> CreatedBy { get; set; }
        public Nullable<System.DateTime> CreationDate { get; set; }
    }
}