Retrieving XML from database with Dapper

Perhaps creating a custom type handler can help? Something like:

public class XDocumentTypeHandler : SqlMapper.TypeHandler<XDocument>
{
    public override void SetValue(IDbDataParameter parameter, XDocument value)
    {
       // set value in db parameter.
    }

    public XDocument Parse(object value)
    {
       // parse value from db to an XDocument.
    }
}

You have to add the type handler with SqlMapper.AddTypeHandler().

See a sample implementation.

In the end, I just brute-forced it:

public class Workflow
{
    public Guid InstanceId { get;set; }
    public XDocument StateIn { set { State = value.ToString(); } }
    public string State { get;set; }
    public XDocument StateOut { get { return XDocument.Parse(State); } }
}

Dapper plays with the State value, and I just set the value on StateIn and read it off StateOut. I feel a little bit dirty coming up with a solution like this, but hey, it works.