Prevent lazy loading in nHibernate
- by Ciaran
Hi,
I'm storing some blobs in my database, so I have a Document table and a DocumentContent table. Document contains a filename, description etc and has a DocumentContent property.
I have a Silverlight client, so I don't want to load up and send the DocumentContent to the client unless I explicity ask for it, but I'm having trouble doing this.
I've read the blog post by Davy Brion. I have tried placing lazy=false in my config and removing the virtual access modifier but have had no luck with it as yet.
Every time I do a Session.Get(id), the DocumentContent is retrieved via an outer join. I only want this property to be populated when I explicity join onto this table and ask for it.
Any help is appreciated.
My NHibernate mapping is as follows:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
assembly="Jrm.Model"
namespace="Jrm.Model">
<class name="JrmDocument" lazy="false">
<id name="JrmDocumentID">
<generator class="native" />
</id>
<property name="FileName"/>
<property name="Description"/>
<many-to-one name="DocumentContent" class="JrmDocumentContent" unique="true" column="JrmDocumentContentID" lazy="false"/>
</class>
<class name="JrmDocumentContent" lazy="false">
<id name="JrmDocumentContentID">
<generator class="native" />
</id>
<property name="Content" type="BinaryBlob" lazy="false">
<column name="FileBytes" sql-type="varbinary(max)"/>
</property>
</class>
</hibernate-mapping>
and my classes are:
[DataContract]
public class JrmDocument : ModelBase
{
private int jrmDocumentID;
private JrmDocumentContent documentContent;
private long maxFileSize;
private string fileName;
private string description;
public JrmDocument()
{
}
public JrmDocument(string fileName, long maxFileSize)
{
DocumentContent = new JrmDocumentContent(File.ReadAllBytes(fileName));
FileName = new FileInfo(fileName).Name;
}
[DataMember]
public virtual int JrmDocumentID
{
get { return jrmDocumentID; }
set
{
jrmDocumentID = value;
OnPropertyChanged("JrmDocumentID");
}
}
[DataMember]
public JrmDocumentContent DocumentContent
{
get { return documentContent; }
set
{
documentContent = value;
OnPropertyChanged("DocumentContent");
}
}
[DataMember]
public virtual long MaxFileSize
{
get { return maxFileSize; }
set
{
maxFileSize = value;
OnPropertyChanged("MaxFileSize");
}
}
[DataMember]
public virtual string FileName
{
get { return fileName; }
set
{
fileName = value;
OnPropertyChanged("FileName");
}
}
[DataMember]
public virtual string Description
{
get { return description; }
set
{
description = value;
OnPropertyChanged("Description");
}
}
}
[DataContract]
public class JrmDocumentContent : ModelBase
{
private int jrmDocumentContentID;
private byte[] content;
public JrmDocumentContent()
{
}
public JrmDocumentContent(byte[] bytes)
{
Content = bytes;
}
[DataMember]
public int JrmDocumentContentID
{
get { return jrmDocumentContentID; }
set
{
jrmDocumentContentID = value;
OnPropertyChanged("JrmDocumentContentID");
}
}
[DataMember]
public byte[] Content
{
get { return content; }
set
{
content = value;
OnPropertyChanged("Content");
}
}
}
