我将上传文件模型test.iloc[test.index.get_loc('2018-01-08') - 1]
0 5
Name: 2018-01-05, dtype: int64
更改为继承自基本模型，如bellow：
基础模型：
WorkOrderUploadFile我的def generate_files_directory(instance, filename):
url = "%s/%s" % (instance.filepath , filename) # will output something like `images/imgs/test/`
return url
class UploadFile(models.Model):
"""
Base upload model
"""
#filepath = models.CharField(max_length=128, default="images/qiyun_admin_servicemanage_workorder/")
file = models.FileField(upload_to=generate_files_directory)
ctime = models.DateTimeField(auto_now_add=True)
uptime = models.DateTimeField(auto_now=True)
def __str__(self):
return self.file
def __unicode__(self):
return self.file
课程：
WorkOrderUploadFile当我进行游戏时，我得到了以下问题：
class WorkOrderUploadFile(UploadFile):
"""
work order upload file
"""
filepath = models.CharField(max_length=128, default="images/qiyun_admin_servicemanage_workorder/")
但我没有在我的基础模型中添加字段名$ python3 manage.py makemigrations
You are trying to add a non-nullable field 'uploadfile_ptr' to workorderuploadfile without a default; we can't do that (the database needs something to populate existing rows).
Please select a fix:
1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
2) Quit, and let me add a default in models.py
以及如何处理它？我尝试将uploadfile_ptr提供给值但我仍然收到错误，它会报告错误：
1修改
基础模型和子类模型不在同一个项目中。
修改-2
我在我的基本模型中添加了默认值。
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/MySQLdb/cursors.py", line 374, in _do_query
db.query(q)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/MySQLdb/connections.py", line 277, in query
_mysql.connection.query(self, query)
django.db.utils.IntegrityError: (1062, "Duplicate entry '1' for key 'PRIMARY'")
但仍有这个问题。
修改-3
我尝试将Meta添加到基本模型仍然不起作用：
file = models.FileField(upload_to=generate_files_directory, default="")
答案 0 :(得分：0)
简而言之，您需要为models.FileField添加默认值。
这通常是因为原始数据库中有一些现有行并不包含file。因此，当您makemigrations时，db server无法确定此附加列的值。