如何生成 excel 文件并将其作为文件保存到数据库

Question

I have created a function that creates an excel file using xlwt. I was able to download it as file but I want it to be saved to the database first and what I did does not work.

Here's what I did so far.

import xlwt

response = HttpResponse(content_type='application/ms-excel')
response['Content-Disposition'] = 'attachment; filename="excel-file.xls"'

wb = xlwt.Worbook()
# some excel file generating code here
wb.save(response)

return response

After generating the excel file, I tried it to save it to the database but doing this does not work. (Code below)

# file = models.FileField
Reports.objects.create(
   file=wb
)

I have also tried saving it to a stream first but saving it like this also does not work. (Code below)

f = io.StringIO()
wb.save(f)

# file = models.FileField
Reports.objects.create(
   file=f
)

Answer 1

OK, I think I understand what you are asking now.

Unfortunately, the FileField class is designed to save an (uploaded) file in the file system, not the database. This is probably a good thing. Databases are not designed to be used as file systems. But either way, if you use FileField the database will only contain the file name, not the file content.

So my first suggestion is to use FileField and FileSystemStorage as intended. There is some example code in https://docs.djangoproject.com/en/3.0/topics/files/#file-storage that shows how to save some stuff into the default file storage.

Alternatively, if you really want to store your Excel object in the database, then you need to change the FileField to a BinaryField . Then you can do something like this:

  buffer = BytesIO()
  wb.save(buffer)
  // excel = models.BinaryField()
  Reports.object.create(excel=buffer.getValue(), ...)

(There are probably more efficient ways to do this.)