Not an issue of the kata.

The problem is that the query 'join' in your code has not been fixed. The condition for joining is missing.
Perhaps this helps: https://www.postgresql.org/docs/8.3/static/tutorial-join.html

It would be nice if you included the error, but start by removing the distinct.

Which test is the one you think is wrong and what is your result for that test?

No probs :)

I'm sorry it was my fault. All is good.

You are right, we forgot to edit the description: price is the optional parameter, default of it being 30.

Python instructions say each letter will cost £30, but functions is written as accepting two parameters: def billboard(name, price) .
Some test cases take a single argument and some take two, throwing an error while trying to test.

I cannot reproduce it, care to tell me which was the initial random price in that one? 60?

Ruby and Python translations kumited, if you want to approve them; once you do (IF you do, of course), post under here, so that I can edit the description a bit (doing it first would give us merge conflicts...) to point out that £30 should be the default value, but other values might be tested.

matt is right, the input array should be modified, you should not make a copy of it.

That's not an issue, you're just not modifying the original array. You may need to take another approach to solving this kata, Think simple. Good luck! :)