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.

I've been posting about this in various topics but now that it's on Github, I thought maybe it's time to give it a topic of its own. From the README:

My goal is to eventually replicate the keyboard and sound of the bass side of an accordion in an electronic device that accordion players will find easy to adapt to. So far I've built three prototypes:

• Prototype 1 was trying out a Teensy 4 with an audio shield on a breadboard, with 4 bass buttons.
• For prototype 2, I put the buttons on two double-decker circuit boards (9 bass buttons). Here's the Video. You can see the remains of prototype 1 in the background.
• For prototype 3, I built a real case out of wood and laser-cut acrylic panels, to make a desktop device that's more easily portable. This one uses a Teensy 3.6. Here's the Video. I designed it in Onshape and you can look at the CAD model online.

This topic is part of a weekly series. It is meant to be a place for users to discuss their week.

If you have any plans, goals, accomplishments, or even failures, whether they be personal or work related, I'd love to hear about them. This is a place for casual discussion about your week, past, present, and future.

A list of all previous topics in this series can be found here.

So, what (or how) are you doing this week?

A drink coaster goes under a glass or cup, and is intended to catch any condensation or spillage from the glass, to protect the tabletop underneath.

But most coasters are flat.* Any liquid that gathers on them can roll off the edges onto the table. Some coasters are made of a water-absorbing material, like cardboard or cork, but some are made of materials that repel water, like metal or ceramic or plastic.

I ask this because I recently discovered a small coaster-like tray with an upraised lip around the edge. Strictly speaking, it's not a coaster, but it's exactly the right size to be used as a coaster - and, with the upraised lip around the edge, it actually prevents liquid from escaping onto the table.

So why are coasters flat?

(I bought some of the lipped not-coasters to use as coasters. This design makes sense to me. And they happen to look nice as well.)

* It was only while researching coasters online prior to making this post that I discovered that some coasters have lips. Every coaster I've seen in real life is flat.