Ignore queryBean.select(null) calls

[artemik]

Feature Request

I'd like Ebean to ignore .select(null) calls on query beans. I.e. treat null parameter as if no FetchGroup was provided.

new QOrder()
    .select(null)
    ...

Current Behavior and Workaround

Currently, select(null) throws null pointer exception.

If we're in a repository function:

public findSomeOrders(int orderId, ..., FetchGroup fetchGroup) {
    ...

the current workaround is to check whether the provided fetchGroup argument is null and then either:

• don't call .select()
• or default fetchGroup argument to FetchGroup.queryFor(clazz).buildFetchGroup();, i.e. a no-op fetch group, and pass that to select() (instead of avoiding calling select() because it would break query bean chain of calls and would look more ugly)

Why

It's common for repositories to define selection queries and then let calling code decide what referenced entities should actually be loaded eagerly. It's very often that users don't want to select any other referenced entity, they just want the main entity itself, in which case it seems obvious and easy for them not to specify any fetch group at all when calling the repository method, so they pass null, which currently causes the above workaround to be in place in every single repository method. So that's why I think null should be simply ignored.

Another solution option would be to add something like FetchGroup.NOOP, but anyway I don't see why a null should cause an exception instead of being ignored.

It seems like an easy fix of just adding if (fetchGroup == null) return root; into select() method.

[artemik]

Wow that was fast, thanks!