gruuya commented on code in PR #10690:
URL: https://github.com/apache/datafusion/pull/10690#discussion_r1617161884


##########
datafusion/sql/src/unparser/plan.rs:
##########
@@ -271,8 +273,39 @@ impl Unparser<'_> {
                     relation,
                 )
             }
-            LogicalPlan::Distinct(_distinct) => {
-                not_impl_err!("Unsupported operator: {plan:?}")
+            LogicalPlan::Distinct(distinct) => {
+                let (select_distinct, input) = match distinct {
+                    Distinct::All(input) => (ast::Distinct::Distinct, 
input.as_ref()),
+                    Distinct::On(on) => {
+                        let exprs = on
+                            .on_expr
+                            .iter()
+                            .map(|e| self.expr_to_sql(e))
+                            .collect::<Result<Vec<_>>>()?;
+                        let items = on
+                            .select_expr
+                            .iter()
+                            .map(|e| self.select_item_to_sql(e))
+                            .collect::<Result<Vec<_>>>()?;
+                        match &on.sort_expr {
+                            Some(sort_expr) => {
+                                if let Some(query_ref) = query {
+                                    query_ref
+                                        
.order_by(self.sort_to_sql(sort_expr.clone())?);
+                                } else {
+                                    return internal_err!(
+                                "Sort operator only valid in a statement 
context."
+                            );

Review Comment:
   The `order_by`/`sort_by` clause is fetched from the `sqlparser::ast::Query` 
struct while parsing the `DISTINCT ON` query, so it makes sense that it is 
added there when de-parsing
   
https://github.com/apache/datafusion/blob/3dc1773403532752db01da5c545b2bdab415e489/datafusion/sql/src/query.rs#L132-L136
   
   Indeed `sqlparser::ast::Select`s `sort_by` is not being used in DataFusion
   
https://github.com/apache/datafusion/blob/3dc1773403532752db01da5c545b2bdab415e489/datafusion/sql/src/select.rs#L68-L70
   so it also seems that  `SelectBuilder::sort_by` is not needed atm.



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org
For additional commands, e-mail: github-h...@datafusion.apache.org

Reply via email to