Filter is not applied in the "where" clause about jpa-streamer HOT 2 CLOSED

Thank you for your answer, it helps me understand better

from jpa-streamer.

Hi Fernando, thank you for the detailed description of your problem. I would not really describe this as a bug - I'll try to explain why.

Your stream has one filter that leverages the JPAStreamer metamodel, and one that uses an anonymous lambda. These will be handled differently:

• The predicate Film$.name etc. is included in the query you provided where lower(f1_0.film_name) like ? escape as JPAStreamer can translate such predicate to SQL.
• The anonymous lambda however cannot be translated by JPAStreamer as the expression does not hold enough metadata about the underlying field. This is described in the docs here.

jpaStreamer.stream(of(Film.class).joining(Film$.language))
     .filter(Film$.name.containsIgnoreCase("test"))       // this is included in the query 
     .filter(film -> film.language.country.equals("BR"))   // this cannot be translated to SQL
     .forEach(System.out::println);

I am assuming you may also wonder how you can filter on the language property. Unfortunately current the answer is that you cannot filter on the joined entities in the database.

from jpa-streamer.