Ɗaya daga cikin manyan matsalolin tare da tambayoyin samfurin Django shine cewa suna iya zama mai magana sosai. Misali, idan kuna son nemo duk labarai a cikin wani shafi da aka bayar, kuna buƙatar amfani da tambaya kamar haka:
labarai = Blog.objects.all()
Idan kuna son nemo duk labaran da aka buga a watan da ya gabata, kuna buƙatar amfani da tambaya kamar haka:
articles_published_in_the_last_month = Blog.objects.filter(published=Gaskiya)
There are a number of ways to query a Django model. The simplest way is to use the Model.objects.all() method, which will return all objects for that model. If you want to filter the queryset, you can use the Model.objects.filter(**kwargs) method, where kwargs is a dictionary of field names and values to filter on. For example, if you only wanted objects with a certain value for the 'name' field, you could do: Model.objects.filter(name='value') If you want to get a single object from the queryset, you can use the Model.objects.get(**kwargs) method, which will return the first object that matches the given criteria. For example, if you wanted to get an object with a particular 'id' value: Model.objects.get(id=1)
Idan kana son yin odar saitin tambaya, za ka iya amfani da hanyar Model.objects.order_by(field_name), wanda zai ba da odar saitin ta wurin da aka bayar a cikin tsari mai hawa. Hakanan zaka iya amfani da prefix '-' don yin oda a cikin tsari mai saukowa:
Model.objects.order_by ('-suna')
Menene QuerySet
QuerySet tarin samfura ne masu alaƙa waɗanda za'a iya tambaya tare. Hanya ce mai dacewa don haɗa samfuran tare ta yadda zaku iya tambayar su cikin sauƙi azaman naúrar.
Maganar Tambaya
Maganar tambaya hanya ce mai ƙarfi don tace bayanai a cikin Django. Yayi kama da jumlar INA a cikin tambayar SQL, amma ana iya amfani dashi tare da kowane abin ƙira.
Misali, zaku iya amfani da furcin tambaya don nemo duk labaran da take da ta fara da “Yadda ake”:
articles.filter( take__startswith='Yadda ake')
Tambaya Saitin API Reference
API ɗin QuerySet yana ba da hanya don bincika filayen samfuri da bayanan haɗin gwiwa. API ɗin an ƙirƙira shi ne bayan bayanan SQL SELECT, kuma yana ba ku damar tantance filayen da kuke son dawo da su, a cikin wane tsari kuke so a dawo dasu, da layuka nawa na bayanan da kuke son dawowa.
Don amfani da QuerySet API, da farko ƙirƙirar abin ƙira:
daga django.db shigo da samfura aji MyModel(models.Model): suna = model.CharField (max_length=30)
Sannan ƙirƙirar abin tambaya:
tambaya = MyModel.objects.create_query() tambaya.select ('name').order_by('-name')
