I spend more than three days with an issue when trying to insert to a Cloudflare D1 database due to lack of understanding on how things work there. After trying a lot of things I'm documenting the break through here for future reference.

I spend three hours debugging and struggling because of the comment on line 13. I made that change yesterday thinking that it affected my deployment and it wasn't the case but today it created the previously mentioned situation. Be carefull because this are the worse kind of errors (not mentioned on tutorials). That's an example of how working on our own project can help us to get experience.

There should be some config in wrangler.toml to work with a local database in an environment that is not production Execute this to run migrations: wrangler d1 migrations apply --local DB

When stuck on a bug, I step away, take a walk, and come back with fresh eyes. Works every time.

Question to ChatGPT: How to configure cors for a cloudflare worker to allow requests. Response: To configure CORS for a Cloudflare Worker, you must manually set the appropriate Access-Control-* headers in the Worker’s response. Cloudflare Workers don’t have built-in CORS settings—you control everything in code.