and convert that in turn into a deeeeeeeply nested I find that CTEs are the solution to deep nesting. There are very few times that I haven't been able to red

and convert that in turn into a deeeeeeeply nested I find that CTEs are the solution to deep nesting. There are very few times that I haven't been able to reduce the amount of nesting down to 2 levels (just the a single query with a subquery as part of an exists or something). That's obviously a problem if you don't have access to CTEs (mysql) or CTEs are an optimization boundary (postgres), but if you're working with a product that does not have those issues, then CTEs can really clean up a lot of sql.