Function derive_order_by

fn derive_order_by(
    body: &SetExpr<Raw>,
    order_by: &Vec<OrderByExpr<Raw>>,
) -> (Vec<OrderByExpr<Raw>>, Vec<SelectItem<Raw>>, Option<Distinct<Raw>>)

Analyzes a query’s ORDER BY clause to derive an ORDER BY clause that makes numeric references to any expressions in the projection and generated-attribute references to expressions that need to be added as extra columns to the projection list. The rewritten ORDER BY clause is then usable when querying a view that contains the same SELECT as the given query. This function returns both the rewritten ORDER BY clause as well as a list of extra columns that need to be added to the query’s projection for the ORDER BY clause to succeed.