模型的Django默认信息
模型的Django默认信息
提问于 2020-03-25 04:20:58
我有2个模型(时间线一个将包含默认信息，我必须上传，和Pdf的一个包含文件和一个关系的时间线单元格)。我被告知要创建自己的迁移文件，并执行了以下操作，但我收到此错误，并且在网上找不到任何有关它的内容：
File "/Users/fetz/Desktop/parentsuportal/parentsuportal/timeline/migrations/0005_auto_20200324_1721.py", line 33, in addData
Timeline(header = "Transport Support", age = "18-25")
File "/usr/local/lib/python3.7/site-packages/django/db/models/base.py", line 520, in __hash__
raise TypeError("Model instances without primary key value are unhashable")
TypeError: Model instances without primary key value are unhashable我的模型：
HEADER_CHOICES = [
('Financial Support', 'Financial Support'),
('Educational Support', 'Educational Support'),
('Governmental Support', 'Governmental Support '),
('Charity Support Groups', 'Charity Support Groups'),
('Therapy Support', 'Therapy Support '),
('Transport Support', 'Transport Support ')
]
AGE_CHOICES = [
('0-4', '0-4'),
('4-11', '4-11'),
('11-18', '11-18'),
('18-25', '18-25')
]
class Timeline(models.Model):
header = models.CharField(max_length=30, choices=HEADER_CHOICES)
age = models.CharField(max_length=6, choices=AGE_CHOICES)
class Pdf(models.Model):
pdf = models.FileField(upload_to='timelinepdfs')
timeline = models.ForeignKey(Timeline, on_delete=models.CASCADE)我的迁移文件：
from django.db import migrations
def addData(apps, schema_editor):
# We can't import the Person model directly as it may be a newer
# version than this migration expects. We use the historical version.
Timeline = apps.get_model("timeline", "Timeline")
timeline = {
Timeline(header = "Financial Support", age = "0-4"),
Timeline(header = "Financial Support", age = "4-11"),
Timeline(header = "Financial Support", age = "11-18"),
Timeline(header = "Financial Support", age = "18-25"),
Timeline(header = "Educational Support", age = "0-4"),
Timeline(header = "Educational Support", age = "4-11"),
Timeline(header = "Educational Support", age = "11-18"),
Timeline(header = "Educational Support", age = "18-25"),
Timeline(header = "Governmental Support", age = "0-4"),
Timeline(header = "Governmental Support", age = "4-11"),
Timeline(header = "Governmental Support", age = "11-18"),
Timeline(header = "Governmental Support", age = "18-25"),
Timeline(header = "Charity Support Groups", age = "0-4"),
Timeline(header = "Charity Support Groups", age = "4-11"),
Timeline(header = "Charity Support Groups", age = "11-18"),
Timeline(header = "Charity Support Groups", age = "18-25"),
Timeline(header = "Therapy Support", age = "0-4"),
Timeline(header = "Therapy Support", age = "4-11"),
Timeline(header = "Therapy Support", age = "11-18"),
Timeline(header = "Therapy Support", age = "18-25"),
Timeline(header = "Transport Support", age = "0-4"),
Timeline(header = "Transport Support", age = "4-11"),
Timeline(header = "Transport Support", age = "11-18"),
Timeline(header = "Transport Support", age = "18-25")
}
timeline.save()
class Migration(migrations.Migration):
dependencies = [
('timeline', '0004_auto_20200323_1947'),
]
operations = [
migrations.RunPython(addData),
]回答 1
Stack Overflow用户
回答已采纳
发布于 2020-03-25 05:14:15
您需要先保存时间轴实例，然后才能在集中使用它。这是因为set使用__hash__方法来标识实例(以便集合具有惟一的项)，而Django Model类的__hash__方法需要pk。解决方案是使用不同的集合类，比如list并对其进行迭代。
timelines = [
Timeline(header = "Financial Support", age = "0-4"),
Timeline(header = "Financial Support", age = "4-11"),
...
]
for timeline in timelines:
timeline.save()或者你可以使用：
Timeline.objects.create(header = "Financial Support", age = "0-4")
Timeline.objects.create(header = "Financial Support", age = "4-11")
...或者如果你担心它们已经存在：
Timeline.objects.get_or_create(header = "Financial Support", age = "0-4")
Timeline.objects.get_or_create(header = "Financial Support", age = "4-11")
...页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/60838705
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