Transform SQL Query to LINQ

Question

I would like if someone helps me to convert this SQL Query to LINQ syntax.

SELECT i.Id, i.Condomino as Condomino, i.Interno as Interno, 
    p.NomePiano as NomePiano, s.Nome as NomeCondominio,
    m.millesimi_fabbisogno_acs, m.millesimi_fabbisogno_riscaldamento
    FROM Interni i
    INNER JOIN Piani p ON i.IdPiano = p.Id
    INNER JOIN Stabili s ON i.IdStabile = s.Id
    LEFT JOIN MillesimiTabellaC m ON i.Id = m.idInterno
    WHERE s.IdCondominio = {0}

I tried using something like this, but is not working..

return _Db.Interni.Include("Piani").Where(x => x.Piani.IdCondominio == iidcond).ToList();

Answer 1

I made it on-the-spot (so it's not tested), but perhaps it's enough to give you the idea. I'm also assuming that your DB model has foreign keys set up.

var result = _db.Interni
                .Where(i => i.Stabili.IdCondominio = [value])
                .Select(i => new
                             {
                                 i.Id,
                                 Condomino = i.Condomino, 
                                 Interno = i.Interno,
                                 NomePiano = i.Piani.NomePiano,
                                 NomeCondominio = i.Stabili.Nome,
                                 i.MillesimiTabellaC.millesimi_fabbisogno_acs, 
                                 i.MillesimiTabellaC.millesimi_fabbisogno_riscaldamento
                             })
                .ToList();

update

In case you don't have a foreign key between Interni and MillesimiTabellaC , try this:

var result = _db.Interni
                .Include(i => i.Piani)
                .Include(i => i.Stabili)
                .Where(i => i.Stabili.IdCondominio = [value])
                .Select(i => new
                             {
                                Interni = i,
                                MillesimiTabellaC = _db.MillesimiTabellaC.Where(m => i.Id = m.idInterno)
                             })
                .Select(x => new
                             {
                                 Id = x.Interni.Id,
                                 Condomino = x.Interni.Condomino, 
                                 Interno = x.Interni.Interno,
                                 NomePiano = x.Interni.Piani.NomePiano,
                                 NomeCondominio = x.Interni.Stabili.Nome,
                                 x.MillesimiTabellaC?.millesimi_fabbisogno_acs, 
                                 x.MillesimiTabellaC?.millesimi_fabbisogno_riscaldamento
                             })
                .ToList();