Function to_order_by_exprs_with_select

datafusion/sql/src/query.rs:390–428

Returns the order by expressions from the query with the select expressions.

(
    order_by: Option<OrderBy>,
    select_exprs: Option<&Vec<Expr>>,
)

/// Returns the order by expressions from the query with the select expressions.
pub(crate) fn to_order_by_exprs_with_select(
    order_by: Option<OrderBy>,
    select_exprs: Option<&Vec<Expr>>,
) -> Result<Vec<OrderByExpr>> {
    let Some(OrderBy { kind, interpolate }) = order_by else {
        // If no order by, return an empty array.
        return Ok(vec![]);
    };
    if let Some(_interpolate) = interpolate {
        return not_impl_err!("ORDER BY INTERPOLATE is not supported");
    }
    match kind {
        OrderByKind::All(order_by_options) => {
            let Some(exprs) = select_exprs else {
                return Ok(vec![]);
            };
            let order_by_exprs = exprs
                .iter()
                .map(|select_expr| match select_expr {
                    Expr::Column(column) => Ok(OrderByExpr {
                        expr: SQLExpr::Identifier(Ident {
                            value: column.name.clone(),
                            quote_style: None,
                            span: Span::empty(),
                        }),
                        options: order_by_options,
                        with_fill: None,
                    }),
                    // TODO: Support other types of expressions
                    _ => not_impl_err!(
                        "ORDER BY ALL is not supported for non-column expressions"
                    ),
                })
                .collect::<Result<Vec<_>>>()?;
            Ok(order_by_exprs)
        }
        OrderByKind::Expressions(order_by_exprs) => Ok(order_by_exprs),
    }
}