General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

Have you watched any TV shows recently you want to discuss? Any shows you want to recommend or are hyped about? Feel free to discuss anything here.

Please just try to provide fair warning of spoilers if you can.

Recently I got for free an old Zeiss Super Ikonta 531/2, it's a medium format foldable camera from 1936. It was in decent shape but the lens was very foggy. Fungi can grow on lenses but I think it was just general dirt. Opening it was a bit tricky (I had to get watching-making tools, because the screws are very tiny) but I managed to clean the lenses quite well. I shot a first roll but the focus was off, so I had to make sure the front lens element was at the right distance, using some semi-transparent tape on the back of the camera to see the image.

Then I shot a second roll and developed it myself, which was also a first (it's not super hard though), I had no idea if the images would come out good, or even at all (wasn't even sure I loaded the developing tank correctly). Seeing the images come out of the tank for the first time is quite magical, and they came out great (some of them at least...) :

https://imgur.com/a/bF817x9

Even with my crappy development & scanning I can get high-res images that compete with my expensive digital camera. The lens (Tessar 105mm, f3.8) is quite sharp wide open (statue shot) and I even took a long exposure shot at night using a release cable. The process is very slow and focusing is hard, but it's quite fun and rewarding. These kind of cameras are very cheap but the rest (film, accessories, development, repairs, ...) not so much.

This thread is posted weekly - please try to post all relevant US political content in here, such as news, updates, opinion articles, etc. Extremely significant events may warrant a separate topic, but almost all should be posted in here.

This is an inherently political thread; please try to avoid antagonistic arguments and bickering matches. Comment threads that devolve into unproductive arguments may be removed so that the overall topic is able to continue.

As part of a weekly series, these topics are a place for users to casually discuss the things they did — or didn't do — during their weekend. Did you make any plans? Take a trip? Do nothing at all? Tell us about it!

I have heard just a little bit about the language Crystal every so often, probably since it was first mentioned on /r/programming. From what I know, it's Ruby-like syntax but with a static type system, which seems like a big benefit to me.

I written just a little bit of Ruby, so the syntax isn't very familiar to me, and I haven't bothered trying Crystal out, but I'm curious to know what kinds of things people do with it.

So, my questions are: Do you have any experience with Crystal? If so, what have you used it for? Was it a professional or recreational project? How did you like it? What about it stood out to you compared to your experiences with other languages?

Thanks!

This thread is posted weekly, and is intended as a place for more-casual discussion of the coronavirus and questions/updates that may not warrant their own dedicated topics. Tell us about what the situation is like where you live!

A project I'm working on requires me to cover a bit of comedy targeting Lennart Poettering as it's tangentially related, and I'd like to have more context even though it's not strictly necessary. I'm a nontechnical Linux user who used the OS before systemd came around, but really the only impact on my life it's had is that I occasionally use systemctl to control services.

Though I wasn't paying as much attention to the community around the time major distributions switched, I've been casually exposed to criticism of it ever since I came back, and I'd like to make sense of it all and form an opinion beyond "I like Fedora and GNOME and it seems to go hand-in-hand with those". I've read The Biggest Myths, the Wikipedia article, some stuff on freedesktop.org, and of course absorbed the venom slung back and forth over systemd in every FOSS community, but it's hard to get a full picture. And a picture from 2022, for that matter, as a lot of this information comes from its early days. Help me out?

I used to use a random FOSS Python program to manage my blog. The software honestly wasn't the best (partially my own fault for not setting it up super well) and I stopped using it, lost my blog's source code, and haven't updated the blog in a long time because of that. So I'm looking for a static site generator that is simple, well maintained, and no-frills.