An warware: filin tambaya django ba shi da amfani

Babban matsala tare da filayen tambaya django shine cewa ba za su iya sarrafa ƙima mara kyau ba. Idan kayi ƙoƙarin saka ƙima maras kyau a cikin filin tambaya, django zai jefa banda. Wannan na iya zama matsala idan kuna ƙoƙarin amfani da filin a cikin lissafi ko a cikin magana.

I have a model with a field that can be null. I want to query all the objects where this field is null. How do I do this?


A:

<code>MyModel.objects.filter(field__isnull=True)
</code>

Wannan layin code yana tambayar da MyModel abubuwa da tace su da yanayin cewa field ba komai.

Ƙimar banza a cikin Django

Ƙimar banza wani nau'in ƙima ne na musamman a Django wanda ke wakiltar rashin ƙima. Misali, kirtani “null” darajar banza ce.

Lokacin da kuka sanya ƙima maras kyau ga maɓalli, Django yana saita mai canzawa don samun kirtani mara komai azaman abun ciki. Kuna iya amfani da wannan fasalin don ƙirƙirar masu canji waɗanda ke wakiltar komai.

Hakanan zaka iya amfani da ƙimar mara amfani don nuna ƙarshen bayanai a cikin jeri ko ƙamus. Misali, idan kana so ka ƙirƙiri jerin kirtani waɗanda ke ƙunshe da kirtani kawai “null” da “gaskiya”, za ka iya amfani da lambar mai zuwa:

list = ["null","gaskiya"]

Menene filin tambaya

Filin tambaya filin ne na musamman a cikin mahallin gudanarwa na Django wanda ke ba ku damar gudanar da tambayoyin SQL akan bayanan ku.