Help with a problem in the web apps tutorial in the Racket docs

Questions & Answers
1

I am a (noob) hobbyist programmer and have worked through the second edition of HtDP. Today I've been reading through Continue: Web Applications in Racket in the docs and I can't seem to get the iteration of the blog example in Section 14: A Persistent Model to run properly. I'm on Windows 11, using DrRacket with Racket v8.10. Running the copypasted code from an app-2.rkt file from DrRacket, the blog successfully loads the main page and any post detail pages, but if I attempt to add a post or comment, I receive the following error message:

open-output-file: error deleting file
  path: C:\Program Files\Racket_v8.10\share\pkgs\web-server-lib\web-server\default-web-root\htdocs\the-blog-data.db
  system error: The system cannot find the file specified.; win_err=2

What is going on here? (And how can I fix it?) My assumption was that the initialize-blog! function is supposed to check the same directory as the model.rkt file that defines it, and then load or create the blog there. But it seems it's trying to do this somewhere else?

Any help would be greatly appreciated, thanks!

2

It seems the example doesn't check that the file exists before attempting to delete it. (Or maybe there is a step to make the db?)

As a first attempt to fix the problem, I'd simply make an empty file in:

C:\Program Files\Racket_v8.10\share\pkgs\web-server-lib\web-server\default-web-root\htdocs\the-blog-data.db

This way the delete step can run successfully.

Since you file ends in .db maybe the issue is that you parts of your program comes from the tutorial before databases are introduced?

You can compare your program with: