I have an issue with mapping, simplified my relationship looks like this. I have parent class:
public abstract class DocumentType
{
public virtual int Id { get; set; }
public virtual string Name { get; set; }
}
and two subclasses:
public class UploadedFileDocument : DocumentType
{
}
public class ApplicationFormDocument : DocumentType
{
}
mapped like this:
public DocumentTypeMap()
{
Schema("Core");
Id(x => x.Id);
Map(x => x.Name).Length(128).Not.Nullable();
DiscriminateSubClassesOnColumn("Type");
}
public class UploadedFileDocumentMap : SubclassMap<UploadedFileDocument>
{
}
public class ApplicationFormDocumentMap : SubclassMap<ApplicationFormDocument>
{
}
Then I have another entity with a FK to DocumentType, mapped like this:
public FileConversionMap()
{
Schema("Core");
Id(x => x.Id);
References(x => x.Application).Not.Nullable();
References(x => x.DocumentType).Not.Nullable().Fetch.Select();
}
my issue is, when I retrieve rows from the DB like this:
Session.Query<FileConversion>().AsQueryable();
all the rows come back with the DocumentType
being of type DocumentType
, not of the child type (ie the actual type of that property, ie. when i do .GetType()
, either UploadedFileDocument
or ApplicationFormDocument
)
Apologies if this is just me being dim. But how can I determine which type of DocumentType
I have ... is my mapping wrong?
When you look at your generated SQL (adding .ShowSQL()
to your .Database
method), do you see the Type being entered? You should see something similar to:
INSERT
INTO
"Core_DocumentType"
(Name, Type)
VALUES
(@p0, 'ApplicationFormDocument');
select
last_insert_rowid();
@p0 = 'afd' [Type: String (0)]
Using the mappings you provided, it looks fine and I could return the DocumentType
(using SQLite) just fine.
Here's the code I used to reproduce it. I didn't have your FileConversion
object, so please verify that it matches what you need.
DocumentType
public class DocumentType
{
public virtual int Id { get; set; }
public virtual string Name { get; set; }
}
public class DocumentTypeMap : ClassMap<DocumentType>
{
public DocumentTypeMap()
{
GenerateMap();
}
void GenerateMap()
{
Schema("Core");
Id(x => x.Id).GeneratedBy.Identity();
Map(x => x.Name).Length(128).Not.Nullable();
DiscriminateSubClassesOnColumn("Type");
}
}
UploadFileDocument/ApplicationFormDocument
public class UploadedFileDocument : DocumentType
{
public virtual string ContentType { get; set; }
}
public class ApplicationFormDocument : DocumentType
{
}
public class UploadFileDocumentMap :
SubclassMap<UploadedFileDocument>
{
public UploadFileDocumentMap()
{
GenerateMap();
}
void GenerateMap()
{
Map(x => x.ContentType);
}
}
public class ApplicationFormDocumentMap :
SubclassMap<ApplicationFormDocument>
{
}
FileConversion
public class FileConversion
{
public virtual int Id { get; set; }
public virtual DocumentType DocumentType { get; set; }
}
public class FileConversionMap : ClassMap<FileConversion>
{
public FileConversionMap()
{
GenerateMap();
}
void GenerateMap()
{
Schema("Core");
Id(x => x.Id).GeneratedBy.Identity();
References(x => x.DocumentType).Not.Nullable().Fetch.Select();
}
}
The tests I used (using machine.specifications ):
Context
public class when_discriminating_on_subclass
{
static IList<FileConversion> results;
Establish context = () =>
{
using (var session = DataConfiguration.CreateSession())
{
using (var transaction = session.BeginTransaction())
{
var upload = new UploadedFileDocument
{ Name = "uploaded", ContentType = "test" };
var form = new ApplicationFormDocument
{ Name = "afd" };
session.Save(form);
session.Save(upload);
var formConversion =
new FileConversion { DocumentType = form };
var uploadConversion =
new FileConversion { DocumentType = upload };
session.Save(formConversion);
session.Save(uploadConversion);
transaction.Commit();
}
using (var transaction = session.BeginTransaction())
{
results = session.Query<FileConversion>().AsQueryable().ToList();
transaction.Commit();
}
}
};
Specifications
It should_return_two_results = () =>
results.Count.ShouldEqual(2);
It should_contain_one_of_type_uploaded_file = () =>
results
.Count(x => x.DocumentType.GetType() == typeof(UploadedFileDocument))
.ShouldEqual(1);
It should_contain_one_of_type_application_form = () =>
results
.Count(x => x.DocumentType.GetType() == typeof(ApplicationFormDocument))
.ShouldEqual(1);
}
Debugging through the assertions, I can see that the collection comes back with the two types:
Are you casting them back to the base type anywhere in your mappings or classes?
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