[sqla] Fixing order-by for non-inner-joins (#6862)

(cherry picked from commit 5728946)

superset/connectors/sqla/models.py

@@ -724,15 +724,11 @@ def get_sqla_query(  # sqla
 
                 ob = inner_main_metric_expr
                 if timeseries_limit_metric:
-                    if utils.is_adhoc_metric(timeseries_limit_metric):
-                        ob = self.adhoc_metric_to_sqla(timeseries_limit_metric, cols)
-                    elif timeseries_limit_metric in metrics_dict:
-                        timeseries_limit_metric = metrics_dict.get(
-                            timeseries_limit_metric,
-                        )
-                        ob = timeseries_limit_metric.get_sqla_col()
-                    else:
-                        raise Exception(_("Metric '{}' is not valid".format(m)))
+                    ob = self._get_timeseries_orderby(
+                        timeseries_limit_metric,
+                        metrics_dict,
+                        cols,
+                    )
                 direction = desc if order_desc else asc
                 subq = subq.order_by(direction(ob))
                 subq = subq.limit(timeseries_limit)
@@ -744,6 +740,16 @@ def get_sqla_query(  # sqla
 
                 tbl = tbl.join(subq.alias(), and_(*on_clause))
             else:
+                if timeseries_limit_metric:
+                    orderby = [(
+                        self._get_timeseries_orderby(
+                            timeseries_limit_metric,
+                            metrics_dict,
+                            cols,
+                        ),
+                        False,
+                    )]
+
                 # run subquery to get top groups
                 subquery_obj = {
                     'prequeries': prequeries,
@@ -772,6 +778,19 @@ def get_sqla_query(  # sqla
 
         return qry.select_from(tbl)
 
+    def _get_timeseries_orderby(self, timeseries_limit_metric, metrics_dict, cols):
+        if utils.is_adhoc_metric(timeseries_limit_metric):
+            ob = self.adhoc_metric_to_sqla(timeseries_limit_metric, cols)
+        elif timeseries_limit_metric in metrics_dict:
+            timeseries_limit_metric = metrics_dict.get(
+                timeseries_limit_metric,
+            )
+            ob = timeseries_limit_metric.get_sqla_col()
+        else:
+            raise Exception(_("Metric '{}' is not valid".format(timeseries_limit_metric)))
+
+        return ob
+
     def _get_top_groups(self, df, dimensions):
         cols = {col.column_name: col for col in self.columns}
         groups = []