I saw this question today and it was rightfully put on hold because it was cross-posted to stackoverflow (where it already had an answer anyway).
However, one poster told the OP that "Besides, this is a programming question", i.e. shouldn't be here, should be on stackoverflow.
Now, yesterday dba.stackexchange had 52 questions in total (Tue, 24/09/2019), and 27 the day before (Mon, 23/09). Randomly took the 19th of Sep (Thu) and got ~ 55.
I then looked on stackoverflow and there appears to be at least 700 questions TODAY (and it's not even over...) in the 8 most popular tags with
SQL in the tag (SQL, MySQL, PostgreSQL &c).
So that's not even all the questions relevant to databases (though probably most of them). StackExchange works on UTC, so there's 4 hours of it left, so I'm guessing in the region of 1000 questions a day relevant to databases.
I think that we should try and change things so that even basic SQL questions - in fact anything remotely relevant to databases should come here instead of stackoverflow which has a ridiculous amount of traffic anyway.
On a personal and anecdotal level, I have the "feeling" that questions (are becoming | have become) sparse and we should try to change this.
MySQL&c. in a post to SO, they could be politely reminded that what is on-topic on SO has changed slightly and suggesting they come to DBA.SE? I don't think the technical ins and outs are the issue here - it's more a question of whether both communities (us - i.e. DBA.SE, and then SO) would be in favour of such a (minor) change?