On Mon, 15 Feb 2016 08:56:35 +0100 Clemens Ladisch <clemens at ladisch.de> wrote:
> I don't know why correlated subqueries cannot use values from the > outer query in the ORDER BY or LIMIT clauses; ORDER BY is not part of SELECT! It's not a relational operator. Per the SQL standard -- ORDER BY cannot appear in a subquery. It can appear in only one place: as a kind of post-processor that determines the order in which the rows are delivered to the client. I suspect that's why Postgres ORDER BY doesn't recognize column names in the enclosing scope. If the day ever comes when SQLite can remove language features, internal ORDER BY (and LIMIT) would be at the top of my list, along with double-quotes for strings. --jkl
