Things in MySQL that won't work as expected

Misleading title. While #4 and #3 look like good ways to avoid relying on a horrible MySQL-only misfeature (silently picking arbitrary values from rows you've grouped over), almost all the other behavior (maybe other than LIMIT in #5) is correct according to the ANSI standard and you'll find other databases do the same.

What's with the massive photos that have nothing to do with the article?

Most of the things listed there are not MySQL specific. Here's one that I'm pretty sure is:<p>SELECT * FROM example WHERE value = 'á';<p>where "á" uses UTF-8 encoding.<p>By default this will return rows that match both "á" AND "a", which may or may not be what you want.<p>If you want to make MySQL distinguish between an "a" with an accent and one without, then you need to specify a collation either in the table creation/alter statement, or in your query directly:<p>SELECT * example WHERE value = 'á' COLLATE utf8_bin;

Some of these are just silly. E.g.<p><pre><code> WHERE column IN ('1, 2, 3') </code></pre> How can this ever be expected to work, unless, of course your column is literally '1, 2, 3'? Seems strange to blame MySQL for it. ("MySQL is buggy because it cannot infer meaning from my arbitrary string literals!")

A lot of these come down to NULL makes things not work the way you might expect. Maybe C. J. Date is rightbwhen he says there should be no NULL in the relational model.

haven't we learned that order by rand() is a bad idea?

Do most of these examples work in Postgres?