在Django模型中存储列表的最有效方法是什么？

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class MyClass():
  def __init__(self, name, friends):
      self.myName = name
      self.myFriends = [str(x) for x in friends]

from django.db import models
class myDjangoModelClass():
    myName = models.CharField(max_length=64)
    myFriends = ??? # what goes here?

class Course(models.Model):
   name = models.CharField(max_length=256)
   students = models.ManyToManyField(Student)
class Student(models.Model):
   first_name = models.CharField(max_length=256)
   student_number = models.CharField(max_length=128)
   # other fields, etc...
   friends = models.ManyToManyField('self')

from django.db import models
class SeparatedValuesField(models.TextField):
    __metaclass__ = models.SubfieldBase
    def __init__(self, *args, **kwargs):
        self.token = kwargs.pop('token', ',')
        super(SeparatedValuesField, self).__init__(*args, **kwargs)
    def to_python(self, value):
        if not value: return
        if isinstance(value, list):
            return value
        return value.split(self.token)
    def get_db_prep_value(self, value):
        if not value: return
        assert(isinstance(value, list) or isinstance(value, tuple))
        return self.token.join([unicode(s) for s in value])
    def value_to_string(self, obj):
        value = self._get_val_from_obj(obj)
        return self.get_db_prep_value(value)

from django.db import models
from custom.fields import SeparatedValuesField 
class Person(models.Model):
    name = models.CharField(max_length=64)
    friends = SeparatedValuesField()

class MyModel(models.Model):
    myList = models.TextField(null=True) # JSON-serialized (text) version of your list

import simplejson as json # this would be just 'import json' in Python 2.7 and later
myModel = MyModel()
listIWantToStore = [1,2,3,4,5,'hello']
myModel.myList = json.dumps(listIWantToStore)
myModel.save()

jsonDec = json.decoder.JSONDecoder()
myPythonList = jsonDec.decode(myModel.myList)

>>> myList = [1,2,3,4,5,'hello']
>>> import simplejson as json
>>> myJsonList = json.dumps(myList)
>>> myJsonList
'[1, 2, 3, 4, 5, "hello"]'
>>> myJsonList.__class__
<type 'str'>
>>> jsonDec = json.decoder.JSONDecoder()
>>> myPythonList = jsonDec.decode(myJsonList)
>>> myPythonList
[1, 2, 3, 4, 5, u'hello']
>>> myPythonList.__class__
<type 'list'>

class MyDjangoClass(models.Model):
    name = models.CharField(...)
    friends = models.ManyToManyField("self")
    @property
    def friendlist(self):
        # Watch for large querysets: it loads everything in memory
        return list(self.friends.all())

joseph = MyDjangoClass.objects.get(name="Joseph")
friends_of_joseph = joseph.friendlist

from django.contrib.postgres.fields import ArrayField
from django.db import models
class ChessBoard(models.Model):
    board = ArrayField(
        ArrayField(
            models.CharField(max_length=10, blank=True),
            size=8,
        size=8,
    )

class ChessBoard(models.Model):
    board = ArrayField(
        ArrayField(
            models.CharField(max_length=10, blank=True),
            size=8,
        size=8,
    )

class Bar(models.Model):
    foo = models.TextField(blank=True)
    def set_list(self, element):
        if self.foo:
            self.foo = self.foo + "," + element
        else:
            self.foo = element
    def get_list(self):
        if self.foo:
            return self.foo.split(",")
        return None

bars = Bar()
bars.set_list("str1")
bars.set_list("str2")
list = bars.get_list()
if list is not None:
    for bar in list:
        print bar
else:
    print "List is empty."

from django.db.models import CharField, Model
from django_mysql.models import ListCharField
class Person(Model):
    name = CharField()
    post_nominals = ListCharField(
        base_field=CharField(max_length=10),
        size=6,
        max_length=(6 * 11)  # 6 * 10 character nominals, plus commas
    )

from django.db.models import IntegerField, Model
from django_mysql.models import ListTextField
class Widget(Model):
    widget_group_ids = ListTextField(
        base_field=IntegerField(),
        size=100,  # Maximum of 100 ids in list
    )

>>> Person.objects.create(name='Horatio', post_nominals=['PhD', 'Esq.', 'III'])
>>> Person.objects.create(name='Severus', post_nominals=['PhD', 'DPhil'])
>>> Person.objects.create(name='Paulus', post_nominals=[])
>>> Person.objects.filter(post_nominals__contains='PhD')
[<Person: Horatio>, <Person: Severus>]
>>> Person.objects.filter(post_nominals__contains='Esq.')
[<Person: Horatio>]
>>> Person.objects.filter(post_nominals__contains='DPhil')
[<Person: Severus>]
>>> Person.objects.filter(Q(post_nominals__contains='PhD') & Q(post_nominals__contains='III'))
[<Person: Horatio>]

from django.db.models import CharField, Model
from django_mysql.models import ListCharField
class Person(Model):

在Django模型中存储列表的最有效方法是什么？

13 个回答