fix test

Author: xiedeyantu

datafusion/sql/src/unparser/utils.rs

@@ -239,6 +239,7 @@ fn find_agg_expr<'a>(agg: &'a Aggregate, column: &Column) -> Result<Option<&'a E
         if matches!(agg.group_expr.as_slice(), [Expr::GroupingSet(_)]) {
             // For grouping set expr, we must operate by expression list from the grouping set
             let grouping_expr = grouping_set_to_exprlist(agg.group_expr.as_slice())?;
+            let internal_grouping_columns = 2;
             match index.cmp(&grouping_expr.len()) {
                 Ordering::Less => Ok(grouping_expr.into_iter().nth(index)),
                 Ordering::Equal => {
@@ -247,7 +248,14 @@ fn find_agg_expr<'a>(agg: &'a Aggregate, column: &Column) -> Result<Option<&'a E
                     )
                 }
                 Ordering::Greater => {
-                    Ok(agg.aggr_expr.get(index - grouping_expr.len() - 1))
+                    if index < grouping_expr.len() + internal_grouping_columns {
+                        return internal_err!(
+                            "Tried to unproject column referring to internal grouping column"
+                        );
+                    }
+                    Ok(agg
+                        .aggr_expr
+                        .get(index - grouping_expr.len() - internal_grouping_columns))
                 }
             }
         } else {