python - Django form to query database (models)

Question

So I want to create a super basic form with a single input field which will be used to query my database.

My model (models.py) is as follows:

from django.db import models

class Book(models.Model):
    uid = models.IntegerField(primary_key=True)
    title = models.CharField(max_length=30)
    class Meta:
        db_table = u'books'

forms.py:

from django import forms
from myapp.models import Book

class EnterIDForm(forms.form):
book_id = forms.CharField()
# add a custom clean function to validate that the user input
#  is a valid book ID
def clean_book_id(self):
    try:
        book_id = int(self.cleaned_data["book_id"])
    except:
        book_id = None

    if book_id and Book.objects.filter(uid=book_id).count():
        return book_id
    else:
        raise forms.ValidationError("Please enter a valid book ID number.")

views.py:

from django.shortcuts import render_to_response
from myapp.models import Book

def form_view(request):
    if request.method == "POST":
        # the user has submitted the form, see if we have a book
        book_id_form = EnterIDForm(request.POST) # instantiate our form class with the user data
        if book_id_form.is_valid():
            # if our form is valid, then we have a book_id that works:
            the_book = Book.objects.get(uid=book_id_form.cleaned_data["book_id"])
                return render_to_response("book_template.html", { "the_book": the_book }, context_instance=RequestContext(request))
        # if the form wasn't valid, it will fall through to the other return statement.
    else:
        # If the user didn't submit a form, instantiate a blank one.
        book_id_form = EnterIDForm()
    return render_to_response("form_template.html", { "book_id_form": book_id_form }, context_instance=RequestContext(request))

I want the input field to collect the "uid" from the user and display the all of the data from the Book model instance where uid is some book in the database.

I have an understanding of how the form is tied in with the view, and later templates, but I just cannot seem to get it to work.

I've endlessly searched the Django site and many other resources for an example I can learn from, but nothing.

Anyone mind helping me out?

Thanks.

Answer 1

You can do a simple search here. You do not need any POST calls or form creation. However, if you want to create a form this should still point you in the correct direction.

Try something like this:

search.html:

<form method="get" action="/search/">
  Search Notecards:<input type="text" name="q" id="id_q" value="{{ query }}"/>
  <input type="submit" value="Search" />
</form>

views.py:

from myapp.models import Book
from django.template import RequestContext
from django.shortcuts import render_to_response

def search(request):
    query = request.GET.get('q')
    try:
        query = int(query)
    except ValueError:
        query = None
        results = None
    if query:
        results = Book.objects.get(uid=query)
    context = RequestContext(request)
    return render_to_response('results.html', {"results": results,}, context_instance=context)

results.html:

{% if results %}
  {% for result in results %}
    {{ result.uid }}
    {{ result.xxxx }}
    {{ result.xxxx }}
  {% endfor %}
{% else %}
    <h3 class='error'>Please enter a valid UID</h3>
    <form method="get" action="/search/">
      Search Notecards:<input type="text" name="q" id="id_q" value="{{ query }}"/>
      <input type="submit" value="Search" />
    </form>
{% endif %}