How to make queries directly on the models.py file in django, to fill the fileds with the results?

Question

Hi I want to know If I am able to work directly with queries inside the "models.py" file to make results the default values of some fields. For example:

class NewModel(models.Model): Seats = models.IntegerField(default=<some_result_of_a_query>)...

Thanks: :)

Answer 1

For a project I manage to do it with:

in model.py:

class SQLQueryCache(models.Model):
    SQLquery=models.TextField(blank=True,null=True,unique=True)
    data_refresh_period_in_minuts=models.IntegerField(blank=True,null=True)



class SQLQueryCacheForm (ModelForm):
    def __init__(self, SQLPK,*args, **kwargs):
        super(SQLQueryCacheForm, self).__init__(*args, **kwargs)
        dict_value=SQLQueryCache.objects.filter(pk=SQLPK).values('SQLquery','data_refresh_period_in_minuts')
        for value in dict_value:
            self.fields['SQLquery']=forms.CharField(required=False,initial=value['SQLquery'],widget=forms.Textarea(attrs={'rows': 10, 'cols': 90,'style': 'font-size: 10px'}))
            self.fields['data_refresh_period_in_minuts']=forms.CharField(required=False,initial=value['data_refresh_period_in_minuts'],widget=forms.TextInput(attrs={'type': 'number','style':'width:150px; height:30px'}))

    class Meta:
        model = SQLQueryCache
        fields = ['SQLquery','data_refresh_period_in_minuts']

in view.py:

from .models import SQLQueryCache,SQLQueryCacheForm

def NewDashboardBuilder (request):
    formset['SQL']= SQLQueryCacheForm(SQLPK=componentInstance.SQLquery_FK.pk)
    return render(request, "formTest/Formset.html", {'formset': formset})

in formset.html:

  <!-- SQL part -->
  {% if formset.SQL %}
    <div class="row even">
      <div class='col-'style="padding:5px">
        {{ formset.SQL.as_p }}
      </div>
    </div>

Answer 2

You can define a method on the model that returns the value you want and point the default of your field to that method.