What is the best way to store byte array in SQL database using NHibernate?

Question

I have an array of bytes in my C# class, and need to persist it into a SQL Server 2005 database using NHibernate. What SQL data type should I use for the column, and how do I got about using NHiberante to do the persistance for me? If the answer is a custom NHibernate type, is there any sample code knicking around to do this?

Would it just be easier to convert the byte array to a string and persist it in a varcahr column?

Answer 1

BinaryBlob应该为您生成正确的VarBinary列。

Answer 2

Another way, using the "image" column type in mssql which dynamically allocates to fit very large files like pictures, here's an example.

The hbm.xml:

<property name="Photo" column="Photo" type="BinaryBlob" not-null="true"></property>

The class property:

private byte[] _photo;

public virtual byte[] Photo
{
  get { return _photo; }
  set { _photo = value; }
}

The Test, using a helper to get the nhibernate session:

  Image image = Image.FromFile(@"C:\Documents and Settings\someuser\Desktop\logoTop.gif");
  byte[] imageByte;
  using (MemoryStream ms = new MemoryStream())
  {
    image.Save(ms, ImageFormat.Gif);
    imageByte = ms.ToArray();
  }

  NHSession sessionManager = new NHSession();
  using (ISession session = sessionManager.GetSession())
  using (ITransaction tx = session.BeginTransaction())
    try
    {
      MyPhoto photo = new MyPhoto();
      photo.Photo = imageByte;
      session.Save(photo);
      session.Refresh(photo);
      Console.WriteLine(photo.EverifyPhotoId);
      tx.Commit();
    }
    catch (HibernateException)
    {
      if (tx.IsActive)
        tx.Rollback();
      throw;
    }