findIds (find the list of ids of a given query)

If you're only interested in the Ids of a given model, you can use the findIds method on the query The following code retrieves a list of Ids.
List<Long> ids = Ebean.createQuery(Customer.class).where().ilike("name", "Rob%"").findIds();
for (Long id : ids) {
  // Do something with the ID's
}

The generated SQL only selects the id from the table (even if you use the select clause)

select t0.id from Customer t0 where lower(t0.name) like 'Rob%'