Question

I am using EF4 and creating classes through the Entity design surface then generating the database from them. I want to add an attribute to some of the classes to show the timestamp they were last updated.

I have added a Version attribute to them, but I don’t know which .Net datatype to associate with them so they become either Timestamp or RowVersion in the database when it is generated.

Any ideas?

Answer 1

You use byte[] type for rowversion/timestamp

Example use: http://www.ienablemuch.com/2011/07/using-checkbox-list-on-aspnet-mvc-with_16.html

If you are in the designer, just type in byte[] or System.Byte[], I think the field types dropdown selection on EF designer can be typed-in upon.

Given this DDL

create table Movie
(
MovieId int identity(1,1) not null primary key,
MovieName varchar(100) not null unique,
MovieDescription varchar(100) not null unique,
YearReleased int not null,
Version rowversion  -- rowversion and timestamp are alias of each other
);

This is the class mapping:

public class Movie
{
    [Key]
    public virtual int MovieId { get; set; }
     
    [   Required, Display(Name="Title")
    ]   public virtual string MovieName { get; set; }
     
    [   Required, Display(Name="Description")
    ]   public virtual string MovieDescription { get; set; }
     
    [   Required, Display(Name="Year Released"), Range(1900,9999)
    ]   public virtual int? YearReleased { get; set; }
     
    [Timestamp]
    // byte[] is the rowversion/timestamp .NET type
    public virtual byte[] Version { get; set; }  
 
     
    public virtual IList<Genre> Genres { get; set; }              
}