Tricky query question using QueryDSL & SD JPA

[matthewadams]

Ok, I've got two entities from a legacy codebase involved in this query, and I'm not sure how to combine them. I'm also using Spring Data JPA with QueryDSL. Entities first:

@Entity public class Foo {
  @Id Long id;
  String name;
  // other attributes...
}

@Entity public class Bar {
  @Id Long id;
  Long fooId; // NOTE: the Foo id, **not** the entity
  String status;
  // other attributes...
}

Note that Foo has no knowledge of its Bars, and Bar has a many-to-one relationship to Foo, but manifested as an attribute holding the id of the Foo (not a @ManyToOne Foo foo -- remember, this is a legacy codebase).

Now, I want to find all Foos with a given name where there exists at least one Bar with a given id and a status that is not "DELETED" and whose fooId is equal to the corresponding Foo's id. How would I formulate that query using QueryDSL?

// method impl inside custom SD JPA QueryDslPredicateExecutor<Foo> repository

public List<Foo> findByNameWithNotDeletedBarAndBarFooId(String name, long barId) {
  QFoo foo = QFoo.foo; // generated by QueryDSL APT
  QBar bar = QBar.bar; // generated by QueryDSL APT

  Predicate p = new BooleanBuilder()
    .and(name != null && (name = name.trim()).length() > 0 ? foo.name.eq(name) : null)
    .and(bar.id.eq(barId))
    .and(bar.status.ne("DELETED"));
  
  // how can you include condition "where bar.fooId equals foo.id" & combine with Predicate p?

  return findAll(???);
}