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Tomas Pavlik
26,726 PointsPython app - databases
Hi people, as I am learnin Python, I am trying to build my own app. It's a small app for banknote collectors. I already fugured out, how to make data persistent by saving everything into a text file. In the database course taught by Kenneth, the teacher showed us how to save objects into the database. I tried the same - (look into the mynotes.py file - save_entries function). When I add the notes for the first time, everything seems to be ok, when i try to save entries again, I keep getting IntegrityError saying that the serie column is not unique, but I haven't set it to be unique (see dbmodels.py). What am I doing wrong?
Any help will be appreciated..
Tomas
3 Answers
Jeff Wilton
16,646 PointsI think the problem is that you are trying to create the same record multiple times, instead of updating the existing record, therefore resulting in a database integrity error. I'm wondering what you are using for a primary key (is it somehow automatically created?). You should write some additional code to determine if a record already exists before trying to save it, if it exists then do an update instead of a create, and vice-versa.
If you are looking to make a web app version in the future, I would highly recommend switching to Flask or Django, both of which will handle some of the database trickiness for you.
Hope this helps!
Tomas Pavlik
26,726 PointsHi Jeff, thanks a lot for your reply. I will try some test before writing to the database. About the primary key, I did not create it, so it must be somehow created automatically... I think. And thanks for the recommendation, after I solve this database problem, I will definitely try Django (there is a course on Django I believe..).
Tomas
Tomas Pavlik
26,726 PointsSo I tried to add some additional code - look here - All the values are unique, but... when I print out the objects in the banknote list, all the objects use only 2 addresses in the memory, this is the problem I think. Any ideas how to solve this?
Tomas