Struct DynSelect 

pub struct DynSelect<D, Output> { /* private fields */ }

The one unavoidable escape hatch in this design: a single static type cannot mean “this table is joined” in one branch of an if and “it isn’t” in another. Only the join skeleton is erased — every column reference was already checked against a concrete Scope before .erase(), and predicates keep the same closed ExprKind/Value representation used everywhere else, with no Box<dyn _> involved.

Composition happens before erasure, which is why DynSelect offers no further .filter()/.join(). It exists only to let two fully-built branches with different join topology unify into one value.

Implementations

impl<D, Output> DynSelect<D, Output>

pub fn limit(self, n: impl IntoRowCount) -> Self

LIMIT/OFFSET survive erasure because they reference nothing: a row count needs no proof that a table is joined. order_by doesn’t follow them here — a sort key is a column reference, and the scope that would justify it is exactly what .erase() gave up.

pub fn offset(self, n: impl IntoRowCount) -> Self

impl<D: Dialect, Output> DynSelect<D, Output>

pub fn count_sql(&self, _dialect: D) -> (String, Vec<Value>)

The same total Select::count_sql renders. Paging is the reason LIMIT/OFFSET survive erasure, and a page needs a total.

pub fn to_sql(&self, _dialect: D) -> (String, Vec<Value>)