[FIXED] Django: Add result from second queryset to first queryset

Issue

I have two models from two different databases (one read-only) without ForeignKey between the two models (did not get that working, as far i found it isn't possible). In the main model I store the ID from the second model (read-only DB). I want to display multiple records/rows on one view (like al table) There for I want to get the content of the second model with the id from the main model. and combine it to one row. Normal you can get it by the ForeignKey but did won't work with 2 different databases.

What i got (simplified):

model.py

class Overeenkomst(models.Model):
    park = models.IntegerField(blank=False, null=False, default='0')
    object = models.IntegerField(blank=False, null=False, default='0')  # ID from model second database  
    date_start = models.DateField()
    date_end = models.DateField()


class Object(models.Model):
    id = models.IntegerField(db_column='ID', primary_key=True)  # Field name made lowercase.
    nummer = models.IntegerField(db_column='NUMMER', blank=True, null=True)  # Field name made lowercase.
    omschrijving = models.CharField(db_column='OMSCHRIJVING', max_length=50, blank=True, null=True)  # Field name made lowercase.
    idobjectsoort = models.IntegerField(db_column='IDOBJECTSOORT', blank=True, null=True)  # Field name made lowercase.
    idobjecttype = models.IntegerField(db_column='IDOBJECTTYPE', blank=True, null=True)  # Field name made lowercase.
    (.....)

    class Meta:
        managed = False
        db_table = 'OBJECT'
        unique_together = (('nummer', 'idpark', 'id'), ('id', 'idpark', 'idobjecttype', 'idobjectsoort', 'dubbelboeking'), ('code', 'id'),)


    def __str__(self):
        return self.omschrijving

view.py

def ovk_overview(request):
    ctx={}

    overeenkomsten =models.Overeenkomst.objects.filter(park=request.session['park_id'])

    ovk = []
    for overeenkomst in overeenkomsten:
        obj = models.Object.objects.using('database2').filter(pk=overeenkomst.object).values('omschrijving')
        
        ##### Here I Missing a part #####
        

    ctx['overeenkomsten'] = ovk
    return render(request, 'overeenkomsten/overzicht.html', context=ctx)

overzicht.html

{% extends "base.html" %}
{% load static %}

{% block content %} 
<table class='table table-sm'>
    <tr>
        <th>#</th>
        <th>Object</th>
        <th>Start datum</th>
        <th>Eind datum</th>
        <th>&nbsp;</th>
    </tr>

    {% for ovk in overeenkomsten %}
    {{ ovk }}::
    <tr>
        <td>{% now 'Y' %}{{ ovk.park }}{{ovk.object}}{{ovk.id}}</td>
        <td>{{ ovk.object.omschrijving}}</td>
        <td>{{ ovk.date_start|date:"d-m-Y" }}</td>
        <td>{{ ovk.date_end|date:"d-m-Y" }}</td>
        <td><a href="{% url 'overeenkomsten:pdf_vast' ovk.id %}" target="_blank"><button class="btn btn-primary">Download pdf</button></a></td>
    </tr>
    {% endfor %}
</table>
{% endblock %}

I have tried to use list() and chain() (as answer https://stackoverflow.com/a/8171434) but then i get only the values of the Object model and nothing from the Overeenkomsten model.

I hope someone has a answer/idea for me.

Solution

You could do something like this.

views.py

from django.forms.models import model_to_dict 

    def ovk_overview(request):
        ctx={}
    
        overeenkomsten =models.Overeenkomst.objects.filter(park=request.session['park_id'])
    
        ovk = []
        for overeenkomst in overeenkomsten:
            overeenkomst_dict = model_to_dict(overeenkomst)
            obj = models.Object.objects.using('database2').get(pk=overeenkomst.object) #Assumed there is always an obj. If not, change accordingly.
            overeenkomst_dict['omschrijving'] = obj.omschrijving
            ovk.append(overeenkomst_dict) 
            
            
            
    
        ctx['overeenkomsten'] = ovk
        return render(request, 'overeenkomsten/overzicht.html', context=ctx)

overzicht.html

{% extends "base.html" %}
{% load static %}

{% block content %} 
<table class='table table-sm'>
    <tr>
        <th>#</th>
        <th>Object</th>
        <th>Start datum</th>
        <th>Eind datum</th>
        <th>&nbsp;</th>
    </tr>

    {% for ovk in overeenkomsten %}
    {{ ovk }}::
    <tr>
        <td>{% now 'Y' %}{{ ovk.park }}{{ovk.object}}{{ovk.id}}</td>
        <td>{{ ovk.omschrijving }}</td>
        <td>{{ ovk.date_start|date:"d-m-Y" }}</td>
        <td>{{ ovk.date_end|date:"d-m-Y" }}</td>
        <td><a href="{% url 'overeenkomsten:pdf_vast' ovk.id %}" target="_blank"><button class="btn btn-primary">Download pdf</button></a></td>
    </tr>
    {% endfor %}
</table>
{% endblock %}

Answered By - dab92