Function cp_projection_scope 

pub fn cp_projection_scope(scope: &TableScope) -> Option<TableScope>

A copy of scope that resolves sequence accessors, when scope iterates rows and backs the statement’s output SELECT. A FROM-less SELECT gets None: the planner evaluates the accessor itself there, and the item stays an ordinary Computed entry. A nested SELECT (subquery, CTE body, UNION branch, derived table, INSERT or MERGE source) gets None too: the Control Plane evaluates the statement’s output rows only, so the ordinary scope refuses the accessor there.