[Fixed]-What is the best approach to design model fields that is like a list in Django?

I think the best way to organize your ‘SysApp – documents’ relationship, assuming that each document is related to only one sysapp, is to use ForeignKey, as you mentioned.

In that case you’ll only have to create 2 models: the first one is SysApp with a name field and the second is Document with fields title, url to file, description and a foreignkey to SysApp. Now you can create documents and attach them to the sys you want. So you do not need to specify document_2, document_3 etc. fields.

If you need to attach one document to more than one sysapp use ManyToMany instead of ForeignKey.