adding validation annotators to model classes when using Linq-to-SQL

Question

How should I add the following attrubute

[Required(ErrorMessage="...")]

to one of the model properties when my model classes are automatically generated.

There is a solution here, but it seems to be working only on Entity Framework

Answer 1

The same solution can be applied for LINQ to SQL. The snippet the article shows for using the MetadataType will use perfectly well with LINQ to SQL generated classes:

[MetadataType(typeof(MovieMetaData))]
public partial class Movie
{
}

public class MovieMetaData
{
    [Required]
    public object Title { get; set; }

    [Required]
    [StringLength(5)]
    public object Director { get; set; }


    [DisplayName("Date Released")]
    [Required]
    public object DateReleased { get; set; }
}