Splitting row into several nested objects - dapper

Question

I've got the following query:
select id, name, email, supervisor, createdBy, createdAt, changedBy, changedAt from XXX
Now, I'd like to map each row into something that looks like this:
public class Organisation{
public int Id{get; set; }
public string Name{get; set; }
public ContactInfo Contact{get;set;}
public Action CreatedBy{get;set;}
public Action ChangedBy{get;set;}
}
public class ContactInfo{
public string Name{get;set;}
public string Email{get;set;}
}
public class Action{
public string Username{get;set;}
public DateTime At{get;set;}
}
I've seen some examples that show how to partition the info, but it seems like will not work in this example. Can it be done or should I map my query into a helper object which will then be mapped into these classes?
Thanks.
Luis

Answer 1

Dapper allows you to map a single row to multiple objects. This is a
key feature if you want to avoid extraneous querying and eager load
associations.
You can read about it more here
Below is an example:
[Test]
public void Test_Multi()
{
using (var conn = new SqlConnection(#"Data Source=.\sqlexpress;Integrated Security=true; Initial Catalog=foo"))
{
var result = conn.Query<Organisation, ContactInfo, Action, Action, Organisation>(
#"select Id = 100, Name = 'Foo',
Name = 'Contact Name', Email = 'contact#foo.com',
Username = 'The Creator', At = '12/25/2017',
Username = 'The Modifier', At = '12/26/2017' ",
(org, contact, cretedBy, changedBy) =>
{
org.Contact = contact;
org.CreatedBy = cretedBy;
org.ChangedBy = changedBy;
return org;
}, splitOn: "Id, Name, Username, Username").First();
Assert.That(result.Id, Is.EqualTo(100));
Assert.That(result.Contact.Email, Is.EqualTo("contact#foo.com"));
Assert.That(result.CreatedBy.Username, Is.EqualTo("The Creator"));
Assert.That(result.ChangedBy.Username, Is.EqualTo("The Modifier"));
}
}