.. _cookbook_filter_py:

 .. index::
    single: Cookbook Filter

COOKBOOK 4: Wichtige Field Lookups und Filter
********************************************************
Eine Übersicht über die wichtigsten ``Field Lookups`` mit der ``filter()``-Methode.

contains
-------------

.. code-block:: python

    >>> qs = Category.objects.all()
    >>> qs = qs.filter(description__contains='a')
    >>> qs = qs.filter(name__icontains='Super')
    >>>
    >>> # Alle Kategorien, deren Event-Authoren ein  "Alfred" im Vornamen haben
    >>> qs = Category.objects.filter(events__author__first_name__icontains='alfred')


isnull
----------

.. code-block:: python
    
    >>> categories = Category.objects.filter(sub_title__isnull=True)

startswith
-----------

.. code-block:: python
    
    >>> categories = Category.objects.filter(name__startswith='J')
    >>> categories = Category.objects.filter(category__name__startswith='Spo')
    >>> events = Event.objects.filter(author__first_name__startswith='Bilbo')


endswith / iendswith
------------------------------

.. code-block:: python
    
    >>> categories = Category.objects.filter(name__endswith='urm')
    >>> categories = Category.objects.filter(category__name__endswith='rt')
    >>> events = Event.objects.filter(author__last_name__endswith='gins')


gt, gte, lt, lte
------------------------------
Greater than.

.. code-block:: python
    
    >>> categories = Category.objects.filter(num_of_events__gt=5)
    >>> categories = Category.objects.filter(num_of_events__lt=5)
    >>> categories = Category.objects.filter(num_of_events__lte=5)
    >>> categories = Category.objects.filter(num_of_events__gte=5)

SQL Query des Querysets betrachten
------------------------------------------------------------

.. code-block:: python
    
    >>> categories = Category.objects.filter(num_of_events__gt=5)
    >>> categorie.query.__str__()