Django Abfrage Gruppe Datensätze mit erstellt Feld

Question

models.py

class Post(models.Model): 
    caption = models.CharField(max_lenght=200) 
    description = models.TextField() 
    created = models.DateTimeField(auto_now_add=True) 
    modified = models.DateTimeField(auto_now=True) 

Ich bin für eine einzige Django Abfrage suchen, Ergebnisse wie zurück:

data = { 
    "YYYY-MM-DD": [{<post data one>}, {<post data two>}], 
    "YYYY-MM-DD": [{<post data one>}, {<post data two>}], 
    "YYYY-MM-DD": [{<post data one>}, {<post data two>}], 
} 

„YYYY-MM-DD "ist der Datumswert von created Feld in Post Modell

Answer 1

Werfen Sie einen Blick auf die Vorlage regroup Tag.

So etwas sollte funktionieren:

{% regroup posts by created as post_list %} 

<ul> 
{% for row in post_list %} 
    <li>{{ post_list.grouper }} 
    <ul> 
     {% for created in row.list %} 
      <li>{{ created.caption }}: {{ created.description }}</li> 
     {% endfor %} 
    </ul> 
    </li> 
{% endfor %} 
</ul> 

Answer 2

Ich glaube, Sie es mit groupby aus Python-Modul verarbeiten kann.

Ich gebe Ihnen ein Beispiel;

>>> rows = Post.objects.published().values_list('id', 'created') 
>>> rows 
<QuerySet [ 
    (100, datetime.datetime(2017, 2, 9, 14, 35, 9, 358, tzinfo=<UTC>)), 
    (99, datetime.datetime(2017, 2, 9, 14, 35, 0, 760347, tzinfo=<UTC>)), 
    (98, datetime.datetime(2017, 1, 22, 3, 32, 18, 570201, tzinfo=<UTC>)), 
    (97, datetime.datetime(2017, 1, 3, 0, 44, 35, 277663, tzinfo=<UTC>)), 
    (96, datetime.datetime(2017, 1, 1, 14, 18, 30, 920143, tzinfo=<UTC>)), 
    (95, datetime.datetime(2016, 12, 24, 3, 31, 2, 370658, tzinfo=<UTC>)), 
    '...(remaining elements truncated)...']> 
>>> 
>>> from itertools import groupby 
>>> items = [] 
>>> for k, v in groupby(rows, key=lambda row: row[1].strftime('%Y-%m-%d')): 
...  data = dict({k: list(dict(v).keys()) }) 
...  items.append(data) 
...  print(data) 
... 
{'2017-02-09': [99, 100]} 
{'2017-01-22': [98]} 
{'2017-01-03': [97]} 
{'2016-10-09': [81]} 
{'2016-10-07': [80, 79]} 
{'2016-10-05': [78]} 
{'2016-10-04': [77]} 
{'2016-10-02': [1, 2, 3, 4, 5, 6, 7]} 
>>> items 
[ 
    {'2017-02-09': [99, 100]} 
    {'2017-01-22': [98]} 
    {'2017-01-03': [97]} 
    {'2016-10-09': [81]} 
    {'2016-10-07': [80, 79]} 
    {'2016-10-05': [78]} 
    {'2016-10-04': [77]} 
    {'2016-10-02': [1, 2, 3, 4, 5, 6, 7]} 
] 

Meine bisherigen Tests sind die Werte id/pk von den Objekten. Sie können auch eine Funktion erhalten title, slug oder sonst .. ein Beispiel erstellen:

>>> def get_titles(ids): 
...  final_titles = [] 
...  for id in ids: 
...   final_titles.append(Post.objects.get(id=id).title) 
...  return final_titles 
>>> 
>>> items = [] 
>>> for k, v in groupby(rows, key=lambda row: row[1].strftime('%Y-%m-%d')): 
...  titles = get_titles(list(dict(v).keys())) 
...  items.append(dict({k: titles})) 
>>> items 
[ 
    {'2017-02-09': ['Test Post 1', 'Test Post 2']}, 
    {'2017-01-22': ['Fixed DNS PROBE on Ubuntu']}, 
    {'2017-01-03': ['Django: Custom safe excludes from dangerous XSS Injection']}, 
    {'2017-01-01': ['DracEditor - Django Markdown Editor built for Dracos Linux']}, 
    {'2016-12-24': ['Top 10 Python libraries of 2016']}, 
    {'2016-12-19': ['How to custom html choose image upload for django markdownx']}, 
    {'2016-12-18': ['Command to handle deploy Django with quickly']} 

    .... 
] 

standardmäßig, wenn Sie mit final_titles.append(Post.objects.get(id=id)) bereiten models.Post

die string aus Funktion von def __unicode__(self): oder def __str__(self): innen zurückkehren sollte

Und schließlich, einfach, um Metadaten von den Objekten zu erhalten.

def get_data(ids): 
    final_data = [] 
    for id in ids: 
     post = Post.objects.get(id=id) 
     final_data.append({'title': post.title, 'created': post.created, 'slug': post.slug}) 
    return final_data 

items = [] 
rows = Post.objects.published().values_list('id', 'created') 

for k, v in groupby(rows, key=lambda row: row[1].strftime('%Y-%m-%d')): 
    data = get_data(list(dict(v).keys())) 
    items.append(dict({k: data})) 

Ergebnis items;

[ 
    { 
    '2017-02-09': [ 
     { 
     'created': datetime.datetime(2017, 2, 9, 3, 32, 18, 570201, tzinfo=<UTC>), 
     'title': 'Test Post 1', 
     'slug': 'test-post-1' 
     }, 
     { 
     'created': datetime.datetime(2017, 2, 9, 2, 21, 9, 570201, tzinfo=<UTC>), 
     'title': 'Test Post 2', 
     'slug': 'test-post-2' 
     } 
    ] 
    }, 
    { 
    '2017-01-22': [ 
     { 
     'created': datetime.datetime(2017, 1, 22, 3, 32, 18, 570201, tzinfo=<UTC>), 
     'title': 'Fixed DNS PROBE on Ubuntu', 
     'slug': 'fixed-dns-probe-on-ubuntu' 
     } 
    ] 
    }, 
    { 
    '2017-01-03': [ 
     { 
     'created': datetime.datetime(2017, 1, 3, 0, 44, 35, 277663, tzinfo=<UTC>), 
     'title': 'Django: Custom safe excludes from dangerous XSS Injection', 
     'slug': 'django-custom-safe-excludes-from-dangerous-xss-injection' 
     } 
    ] 
    }, .... 
]