基于answer of régis-b我写了一些代码,允许在Django 1.6“loaddata”管理命令中使用自然键而不升级到1.7。我选择这种方式是因为我的项目完全升级可能会很痛苦。此解决方案可以被视为临时性的。
树结构:
├── project_main_app
│ ├── __init__.py
│ ├── backports
│ │ ├── __init__.py
│ │ └── django
│ │ ├── __init__.py
│ │ └── deserializer.py
│ └── monkey.py
project_main_app /反向移植/ django的/ deserializer.py
from __future__ import unicode_literals
from django.conf import settings
from django.core.serializers import base
from django.core.serializers.python import _get_model
from django.db import models, DEFAULT_DB_ALIAS
from django.utils.encoding import smart_text
from django.utils import six
def Deserializer(object_list, **options):
"""
Deserialize simple Python objects back into Django ORM instances.
It's expected that you pass the Python objects themselves (instead of a
stream or a string) to the constructor
"""
db = options.pop('using', DEFAULT_DB_ALIAS)
ignore = options.pop('ignorenonexistent', False)
models.get_apps()
for d in object_list:
# Look up the model and starting build a dict of data for it.
Model = _get_model(d["model"])
data = {Model._meta.pk.attname: Model._meta.pk.to_python(d.get("pk", None))}
m2m_data = {}
model_fields = Model._meta.get_all_field_names()
# Handle each field
for (field_name, field_value) in six.iteritems(d["fields"]):
if ignore and field_name not in model_fields:
# skip fields no longer on model
continue
if isinstance(field_value, str):
field_value = smart_text(field_value, options.get("encoding", settings.DEFAULT_CHARSET), strings_only=True)
field = Model._meta.get_field(field_name)
# Handle M2M relations
if field.rel and isinstance(field.rel, models.ManyToManyRel):
if hasattr(field.rel.to._default_manager, 'get_by_natural_key'):
def m2m_convert(value):
if hasattr(value, '__iter__') and not isinstance(value, six.text_type):
return field.rel.to._default_manager.db_manager(db).get_by_natural_key(*value).pk
else:
return smart_text(field.rel.to._meta.pk.to_python(value))
else:
m2m_convert = lambda v: smart_text(field.rel.to._meta.pk.to_python(v))
m2m_data[field.name] = [m2m_convert(pk) for pk in field_value]
# Handle FK fields
elif field.rel and isinstance(field.rel, models.ManyToOneRel):
if field_value is not None:
if hasattr(field.rel.to._default_manager, 'get_by_natural_key'):
if hasattr(field_value, '__iter__') and not isinstance(field_value, six.text_type):
obj = field.rel.to._default_manager.db_manager(db).get_by_natural_key(*field_value)
value = getattr(obj, field.rel.field_name)
# If this is a natural foreign key to an object that
# has a FK/O2O as the foreign key, use the FK value
if field.rel.to._meta.pk.rel:
value = value.pk
else:
value = field.rel.to._meta.get_field(field.rel.field_name).to_python(field_value)
data[field.attname] = value
else:
data[field.attname] = field.rel.to._meta.get_field(field.rel.field_name).to_python(field_value)
else:
data[field.attname] = None
# Handle all other fields
else:
data[field.name] = field.to_python(field_value)
# The key block taken from Django 1.7 sources
obj = build_instance(Model, data, db)
yield base.DeserializedObject(obj, m2m_data)
# This is also taken from Django 1.7 sources
def build_instance(Model, data, db):
"""
Build a model instance.
If the model instance doesn't have a primary key and the model supports
natural keys, try to retrieve it from the database.
"""
obj = Model(**data)
if (obj.pk is None and hasattr(Model, 'natural_key') and
hasattr(Model._default_manager, 'get_by_natural_key')):
natural_key = obj.natural_key()
try:
obj.pk = Model._default_manager.db_manager(db).get_by_natural_key(*natural_key).pk
except Model.DoesNotExist:
pass
return obj
project_main_app/monkey.py
def patch_all():
import django.core.serializers.python
import project_main_app.backports.django.deserializer
# Patch the Deserializer
django.core.serializers.python.Deserializer = project_main_app.backports.django.deserializer.Deserializer
project_main_app/init。PY
from project_main_app.monkey import patch_all
patch_all()
所以在此之后我只是添加了一些东西,我的模型变得像
class TemplateManager(models.Manager):
"""1"""
def get_by_natural_key(self, name):
return self.get(name=name)
class Template(models.Model):
name = models.CharField(_('name'), max_length=100)
content = models.TextField(_('content'), blank=True)
objects = TemplateManager() # 2
def natural_key(self):
"""3"""
return (self.name,)
,如果灯具有一个空的PK喜欢
[
{
"pk": null,
"model": "dbtemplates.Template",
"fields": {
"content": "Some content",
"name": "product"
}
}
]
标准命令./ manage.py loaddata dbtemplates.Template更新或插入对象匹配名称场。
警告:所有的自然关键组件(如我的例子中的“名称”)必须在数据库中具有唯一值。正确的方法是在定义模型时通过添加参数“unique = True”来设置它们的唯一性。
非常感谢它解决了我的问题!稍后我将发布移植在Django 1.6下为项目编写的这个功能的源代码。 – zen11625