LazyLoad a column

I have a table where one of the columns is an image. I would like to get the data from that table, but selectively load the byte array from that column only when I need it. Is there a way to programaticly tell lightspeed which columns to select when getting a record from the database, without having to have 2 different objects in my model, one with, and one without the image column?

Yes, there is, and it is -- paradoxically -- controlled by the EagerLoad attribute.

What you need to do is mark the fields that should be conditionally loaded with the [EagerLoad(AggregateName="...")] attribute.  (In the designer, select the property and enter a name in the Aggregates box.)

By default, such fields will be lazy loaded -- LightSpeed will not fetch them from the database when you load the entity, but will go back and get them when they are accessed.

But if you know you *are* going to need those fields, you can specify Query.AggregateName (or use the LINQ WithAggregate() operator).  Setting this tells LightSpeed to eager-load all fields with the specified aggregate name.  Thus:

[EagerLoad("WithImage")]  // designer: set Aggregates to WithImage
private byte[] _imageData;

unitOfWork.Products.First();  // _imageData will be lazy-loaded
unitOfWork.Products.WithAggregate("WithImage").First();  // _imageData will be eager-loaded

Finally, if you are writing your classes by hand, for a lazy-loaded field the property getter must call Get(field) rather than just returning the field value.  The designer automatically does this for you.

For more info, see Help Topics > LightSpeed > Querying in the user guide.