Django对象即使在“save”调用之后也不保存-Djangoobjectnotsavingevenafter“save”call

I'm really at a loss because this makes no sense at all. I call save/create an object, and it dosn't show up in the admin site. I even checked the SQLite database with a SQLite Viewer program, which again showed that the item had not been saved.

我真的很迷茫，因为这毫无意义。我调用save/create一个对象，它不会出现在管理站点中。我甚至用一个SQLite查看器程序检查了SQLite数据库，它再次显示项目没有保存。

This is the code that saves the Data object:

这是保存数据对象的代码:

        data = Data(represents=field, for_entry=entry, value="This can be anything")
        # field is a DataField db object and entry is a Entry db object (see model below and paragraph)
        print("B4", data) #<---- Shows that Data has not been assigned an ID/pk
        data.save()
        print("8ER: ", data) #<--- Shows that Data has been assigned an ID/pk

As you can see from my comments, I know that the Data object is assigned an ID after the save call, which I would think meant that it worked. No error is thrown anywhere. field, and entry are all both. Each one seems to be ok, as in they have the right IDs, were retrieved with [table name].objects.get(id=...), and I can save/edit them and their saves change.

正如您从我的注释中看到的，我知道数据对象在save调用之后被分配了一个ID，我认为这意味着它可以工作。任何地方都不会抛出错误。字段和入口都是。每一个看起来都很好，就像在他们有正确的id一样，用[表名].objects.get(id=…)来检索，我可以保存/编辑它们，它们的保存更改。

Even strange, this exact code in a function that is called right before this one works.

甚至奇怪的是，在这个函数之前，这个函数的准确代码是正确的。

This is my model.py (I took out some functions to make it shorter):

这是我的模型。py(我拿出一些函数使它变短):

class Entry(models.Model):
    parent = models.ForeignKey('Entry', blank = True, null = True, default=None) #  The entry this subs. Is left blank for top level entries.
    id_number = models.CharField(max_length=20)
    visible = models.BooleanField()
    data_field = models.ForeignKey('DataField', default=1)  # The field that this entire entry falls under. REDUNDANT BUT NECISSARY

    def __str__(self):
        return str(self.id)+ "-" + str(self.id_number) 

class DataField(models.Model):
    parent = models.ForeignKey('DataField', related_name='parent field', null=True, blank=True, default=1)
    order = models.IntegerField()
    multiple_entries = models.BooleanField(default=True)
    DATA_TYPES = (('t', 'Text'), ('d', 'Date'), ('l', 'List'), ('o', 'Option'), ('b', 'Boolean'), ('f', 'Foreign Key'), ('r', 'Root'), ('bb', 'Branch'), ('i', 'Image'), ('ff', 'File'), ('h', 'Holder'), ('bt', 'Big Text'))  # A number means it is a foreign key. Should go off title.
    foreign_source = models.ForeignKey('DataField', null=True, blank=True) #  Points to DATA FIELD WHO'S MATCHING DATA WILL MAKE UP THE OPTIONS
    data_type = models.CharField(max_length=2, choices=DATA_TYPES, default='t', null=True, blank=True)
    title = models.CharField(max_length=100, null=True, blank=True)
    visibility = models.BooleanField(default=False)

    def __str__(self):
        return str(self.id) + "-" + str(self.title)

    def __eq__(self, other):
        if not isinstance(other, DataField):
            return False
        if self.data_type == 'h':
            return self.title == other.title
        return self.id == other.id


class Data(models.Model):
    represents = models.ForeignKey('DataField')
    for_entry = models.ForeignKey('Entry', null=True)
    value = models.CharField(max_length=1000000)

    def __str__(self):
        return self.represents.title + "-" + str(self.for_entry.id) + "-" + str(self.value) + "-" + str(self.id)

It's possible that I'm missing something obvious, or maybe you need way more information than I can provide to fix it. If there is not enough information, please comment and request more info, or just list possible issues that could be happening.

可能我遗漏了一些明显的东西，或者你需要的信息比我提供的要多。如果没有足够的信息，请评论并请求更多的信息，或者列出可能发生的问题。

2 个解决方案

from django.db import transaction

@transaction.commit_manually
def viewfunc(request):
    ...
    data.save()
    transaction.commit()

p = MyModel.objects.get(pk=myparam)
self.assertEqual(p.my_attr, value) 
myfunc()  # Code that changed the same object p is referencing
self.assertEqual(p.my_attr, new_value)

p = MyModel.objects.get(pk=myparam)
self.assertEqual(p.my_attr, value) 
myfunc()  # Code that changed the same object p is referencing
p = MyModel.objects.get(pk=myparam)
self.assertEqual(p.my_attr, new_value)

class MyModel(models.Model):
    attr = models.IntegerField(default=0)

    def save(self, *args, **kwargs):
        super(MyModel, self).save(*args, **kwargs)
        print('Did this attribute update? (attr):', self.attr)
        print('Save method executed!')

In [3]: a = 1
In [4]: b = a
In [5]: hex(id(a))
Out[5]: '0x100240280'
In [6]: hex(id(b))
Out[6]: '0x100240280'
In [7]: a = 2
In [8]: b
Out[8]: 1
In [9]: hex(id(a))
Out[9]: '0x1002402a0'
In [10]: hex(id(b))
Out[10]: '0x100240280'