Question

I use NHibernate 3.2.0 and I cannot make the LINQ provider generate a proper SQL query for this statement:

var result = (from translation in session.Query<TmTranslation>()
              where translation.Id > 0
              group translation by translation.Language into grp
              select new { Lang = grp.Key.Code }).ToList();

The generated SQL is

select tmtranslat0_.id                        as id32_,
       tmtranslat0_.status                    as status32_,
       tmtranslat0_.text                      as text32_,
       tmtranslat0_.last_revision             as last4_32_,
       tmtranslat0_.fk_id_translation_unit    as fk5_32_,
       tmtranslat0_.fk_id_translator          as fk6_32_,
       tmtranslat0_.fk_id_last_modifier       as fk7_32_,
       tmtranslat0_.fk_id_last_match_category as fk8_32_,
       tmtranslat0_.fk_id_language            as fk9_32_
from   "TRANSLATION" tmtranslat0_
where  tmtranslat0_.id > 0

which, of course leads to loading all the entities from the database and grouping the result set in memory (the result itself is correct).

I would like something like this

select tmtranslat0_.fk_id_language
from   "TRANSLATION" tmtranslat0_
where  tmtranslat0_.id > 0
group by tmtranslat0_.fk_id_language

to be generated instead.

Am I missing something?

Thank you very much.

Answer 1

The only thing I can suggest, is to use QueryOver API.