Rimwe rematambudziko makuru nemibvunzo yeDjango modhi nderekuti vanogona kunge vane verbose. Semuenzaniso, kana iwe uchida kuwana zvese zvinyorwa mune yakapihwa blog, iwe unofanirwa kushandisa mubvunzo seuyu:
zvinyorwa = Blog.objects.all()
Kana iwe waida kuwana zvese zvinyorwa zvakatsikiswa mumwedzi wapfuura, waizoda kushandisa mubvunzo seuyu:
articles_published_in_the_last_month = Blog.objects.filter(yakabudiswa=Chokwadi)
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)
Kana iwe uchida kuhodha queryset, unogona kushandisa iyo Model.objects.order_by(field_name) nzira, iyo inoraira iyo queryset nendima yakapihwa mukukwira kurongeka. Iwe unogona zvakare kushandisa iyo '-' prefix kuronga mukudzika kurongeka:
Model.objects.order_by('-zita')
Chii chinonzi QuerySet
A QuerySet muunganidzwa wemamodheru ane hukama anogona kubvunzwa pamwechete. Iyo inzira iri nyore yekuunganidza mamodheru pamwechete kuti iwe ugone kubvunza zviri nyore seyuniti.
Manzwiro Emibvunzo
Matauriro emubvunzo inzira ine simba yekusefa data muDjango. Yakafanana neiyo WHERE clause mumubvunzo weSQL, asi inogona kushandiswa nechero chinhu chemuenzaniso.
Semuenzaniso, unogona kushandisa izwi remubvunzo kutsvaga zvinyorwa zvese zvine musoro unotanga nekuti "Maitiro":
articles.filter(title__startswith='Maitirwo')
Query Set API Reference
Iyo QuerySet API inopa nzira yekubvunza minda yemuenzaniso uye data rakabatana. Iyo API inoteedzerwa mushure meiyo SQL SELECT statement, uye inokubvumidza kuti utaure kuti ndeapi minda yaunoda kudzoreredza, nenzira ipi yaunoda kuti idzoserwe, uye mitsetse mingani yedata yaunoda kudzorera.
Kuti ushandise QuerySet API, tanga wagadzira chinhu chemuenzaniso:
kubva ku django.db mamodheru ekunze kirasi MyModel(models.Model): zita = modhi.CharField(max_length=30)
Wobva wagadzira chinhu chemubvunzo:
query = MyModel.objects.create_query() query.select('zita').order_by('-zita')
