new @SQLSelect annotation does not work

[gavinking]

If I add:

@SQLSelect(sql = "select name, id from authors where id = $1")

to org.hibernate.reactive.example.nativesql.Author, I get:

Exception in thread "main" java.util.NoSuchElementException
	at java.base/java.util.Collections$EmptyIterator.next(Collections.java:4210)
	at java.base/java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1047)
	at org.hibernate.reactive.loader.ast.internal.ReactiveSingleIdEntityLoaderProvidedQueryImpl.load(ReactiveSingleIdEntityLoaderProvidedQueryImpl.java:51)
	at org.hibernate.reactive.loader.ast.internal.ReactiveSingleIdEntityLoaderProvidedQueryImpl.load(ReactiveSingleIdEntityLoaderProvidedQueryImpl.java:27)
	at org.hibernate.reactive.persister.entity.impl.ReactiveAbstractPersisterDelegate.load(ReactiveAbstractPersisterDelegate.java:235)
	at org.hibernate.reactive.persister.entity.impl.ReactiveSingleTableEntityPersister.doReactiveLoad(ReactiveSingleTableEntityPersister.java:272)

This issue appears to be that the $1 is not recognized. But changing it to ? or ?1 does not seem to help.

[blafond]

@davide Pushed a commit of a Reactive version of ORM's SQLSelectTest to my repo: blafond@e88effd on a 1627-sqlselect branch

I think the current errors are due to two things that are missing in Reactive.

1. During the ReactiveSingleIdEntityLoaderProvidedQueryImpl.load() call, the query object is an instance of a AbstractSelectionQuery rather than a ReactiveAbstractSelectionQuery so query.uniqueResult() is called rather than the reactive method: reactiveUnique(). This is probably due to ReactiveNamedNativeQueryMomento not being created, but NamedNativeQueryMomento instead.
2. The parameter parsing for AbstractSelectionQuery is using the ORM's ParameterParser which only looks for the ? placeholder ... so using $1 won't work

[DavideD]

I gave a look and it seems to happen because we don't wrap the NamedObjectRepository into a ReactiveNamedObjectRepository in ReactiveAbstractPersisterDelegate#createReactiveSingleIdEntityLoader. I haven't looked too much into it, but I think we should add a ReactiveQueryEngine that takes care of this thing. Or, as a quick alternative, something like:

 NamedObjectRepository namedObjectRepository = factory.getQueryEngine().getNamedObjectRepository();
final NamedQueryMemento namedQueryMemento = new ReactiveNamedObjectRepositoryImpl( namedObjectRepository )

We also need to wrap the result of ReactiveNamedObjectRepositoryImpl.java#resolve. Otherwise it won't return a reactive query.

[DavideD]

Also, this seems very wrong:

hibernate-reactive/hibernate-reactive-core/src/main/java/org/hibernate/reactive/loader/ast/internal/ReactiveSingleIdEntityLoaderProvidedQueryImpl.java

Line 54 in 29c518e

return completedFuture( query.uniqueResult() );

[blafond]

thx.. been working on this and pushed a couple changes more changes.