title: ModelChoiceField Concatenate two fields in one field - Django
body: <p>Hi i dont know the way to transform two fields model into one 'custom' to propose a unique field (pass ('fieldA','fieldB') to ('fieldA fieldB').</p>
  
  <p>I am trying to build an inner model function but without excepted result... </p>
  
  <h1>models.py</h1>
  
  <pre><code>class Referencebank(models.Model):
      idtable1 = models.AutoField(db_column='idtable1', primary_key=True)
      genus = models.CharField(max_length=45, blank=True, null=True)
      species = models.CharField(max_length=45, blank=True, null=True)
      subspecies = models.CharField(max_length=45, blank=True, null=True)
  
  
      def getScientifName(self):
          return str(self.genus) + " " + str(self.species);
  
  
      class Meta:
          managed = False
          db_table = 'table1'
  </code></pre>
  
  <h1>forms.py</h1>
  
  <pre><code>class ScientifNameForm(forms.Form):
  
      for ref in Referencebank.objects.all():
  
          queryset = ref.getScientifName();
          print("\n queryset")
  
  
      scientifName = forms.ModelChoiceField(queryset=Referencebank.objects.values_list('genus','species').order_by('genus').distinct(),
                                                     empty_label="(Nothing)",
                                                     required=False,
                                                     help_text="Select the bacteria",label='Scientific Name')
  </code></pre>
  
  <p>In forms.py, the <code>for</code> loop execute correctly the result that i want display in modelchoicefield</p>
  
  <p>I want something like that </p>
  
  <pre><code>        scientifName = forms.ModelChoiceField(queryset=Referencebank.objects.values_list('scientificName').order_by('scientificN').distinct(),
                                                     empty_label="(Nothing)",
                                                     required=False,
                                                     help_text="Select the bacteria",label='Scientific Name')
  </code></pre>