Before we discuss the API for object deletion, lets go back to CayenneModeler and set up some delete rules. Doing this is optional but will simplify correct handling of the objects related to deleted objects.

In the Modeler go to "Artist" ObjEntity, "Relationships" tab and select "Cascade" for the "paintings" relationship delete rule:

Repeat this step for other relationships:

Now save the mapping, and refresh the project in Eclispe.

While deleting objects is possible via SQL, qualifying a delete on one or more IDs, a more common way in Cayenne (or ORM in general) is to get a hold of the object first, and then delete it via the context. Let's use utility class Cayenne to find an artist:

Expression qualifier = ExpressionFactory.matchExp(Artist.NAME_PROPERTY, "Pablo Picasso");
SelectQuery select = new SelectQuery(Artist.class, qualifier);
Artist picasso = (Artist) Cayenne.objectForQuery(context, select);

Now let's delete the artist:

if (picasso != null) {
    context.deleteObject(picasso);
    context.commitChanges();
}

Since we set up "Cascade" delete rule for the Artist.paintings relationships, Cayenne will automatically delete all paintings of this artist. So when your run the app you'll see this output:

INFO: SELECT t0.DATE_OF_BIRTH, t0.NAME, t0.ID FROM ARTIST t0 
      WHERE t0.NAME = ? [bind: 1->NAME:'Pablo Picasso'] - prepared in 6 ms.
INFO: === returned 1 row. - took 18 ms.
INFO: +++ transaction committed.
INFO: --- transaction started.
INFO: DELETE FROM PAINTING WHERE ID = ?
INFO: [batch bind: 1->ID:200]
INFO: [batch bind: 1->ID:201]
INFO: === updated 2 rows.
INFO: DELETE FROM ARTIST WHERE ID = ?
INFO: [batch bind: 1->ID:200]
INFO: === updated 1 row.
INFO: +++ transaction committed.