I have a search form with many filter fields. First I get all fields to a var like: 

```
var obj = (from kb in db.kimlik_bilgileri
            join dbilgi in db.dil_bilgisi on kb.id equals dbilgi.KimlikId
            join okbil in db.okul_bilgileri on kb.id equals okbil.KimlikId
            join kurbil in db.kurum_bilgileri on kb.id equals kurbil.KimlikId
            join ens in db.enstitu on kurbil.kurum_id equals ens.id
            join kadr in db.kadro_unvan on kurbil.kadro_id equals kadr.id
            where kb.Aktifmi == true select new PSearchModel
                    {
                        DilBilgisi = dbilgi,
                        // Diller =  dil,
                        OkulBilgileri = okbil,
                        KadroUnvan = kadr,
                        Enstitu = ens,
                        KimlikBilgileri = kb,
                        KurumBilgileri = kurbil
                    }).ToList();

```

After this, I tried to start filtering by fields like:

```
if (!yabanciDil.IsNullOrWhiteSpace())
{

    obj = (from o in obj
        where o.DilBilgisi.dil_id == Convert.ToInt32(yabanciDil)
           select new PSearchModel
           {
               DilBilgisi = o.DilBilgisi,
               KadroUnvan = o.KadroUnvan,
               KimlikBilgileri = o.KimlikBilgileri,
               OkulBilgileri = o.OkulBilgileri,
               // Diller = o.Diller,
               Enstitu = o.Enstitu,
               KurumBilgileri = o.KurumBilgileri

           }).ToList();
}

```

First `obj` count with 2k data which I expected, but second filter returned count 0. I have 4 or 5 filters also to apply. What did I do wrong or anyone with this condition can describe this.