LINQ External Mapping to Class Library

<Database xmlns="http://schemas.microsoft.com/linqtosql/mapping/2007" Name="Gravel_Dev"><Table Name="dbo.Materials" Member="Material">
<Type Name="Org.Example.System.Material">
  <Column Name="MaterialID" Member="MaterialID" Storage="mMaterialID" DbType="UniqueIdentifier NOT NULL" IsDbGenerated="true" IsPrimaryKey="true"/>
  <Column Name="Code" Member="Code" Storage="mMaterialCode" DbType="Char(4)"/>
  <Column Name="Description" Member="Description" Storage="mDescription" DbType="VarChar(50)"/>
  <Column Name="UnitPrice" Member="UnitPrice" Storage="mUnitPrice" DbType="Decimal(5,2)"/>
</Type>

XmlMappingSource mapping = XmlMappingSource.FromUrl("dbmap.xml");
mContext = new DataContext(Properties.Settings.Default.dbConn, mapping);
reloadTable();