[zasdffaa]

> suggesting using a fully-qualified table name if they actually wanted the table column (t.x in the above example).

I just realised why this was bothering me. That means 't' and 't.x' are actually different variables. In standard SQL it's always the case (right?) that an unqualified variable ('t') is just an convenient shorthand for the fully qualified variable ('t.x', or more fully I suppose, '<db>.<schema>.t.x), and you just broke that.