For a very long time in Rails, it was not possible to combine delete statements with GROUP_BY and HAVING queries. It does seem like something that should have been supported out of the box, but unfortunately was overlooked — until now!

### Before

Using GROUP_BY or HAVING in a delete statement was ignored. Let’s look at an example.

Here, a user has multiple votes, and we’re trying to count users who have less than three votes.

If we do update_all with group and having clause ActiveRecord would ignore it.

However, when we try to delete these users, we end up with an error.

### After

Interestingly, MySQL does not support using DELETE or UPDATE statements in combination with GROUP_BY or HAVING. To circumvent this, the PR uses nested queries.