Allow MetricsControl to aggregate on a column with an expression

superset/connectors/sqla/models.py

@@ -450,10 +450,24 @@ def get_from_clause(self, template_processor=None, db_engine_spec=None):
             return TextAsFrom(sa.text(from_sql), []).alias('expr_qry')
         return self.get_sqla_table()
 
-    def adhoc_metric_to_sa(self, metric):
+    def adhoc_metric_to_sa(self, metric, cols):
+        """
+        Turn an adhoc metric into a sqlalchemy column.
+
+        :param dict metric: Adhoc metric definition
+        :param dict cols: Columns for the current table
+        :returns: The metric defined as a sqlalchemy column
+        :rtype: sqlalchemy.sql.column
+        """
         expressionType = metric.get('expressionType')
         if expressionType == utils.ADHOC_METRIC_EXPRESSION_TYPES['SIMPLE']:
-            sa_column = column(metric.get('column').get('column_name'))
+            column_name = metric.get('column').get('column_name')
+            sa_column = column(column_name)
+            table_column = cols.get(column_name)
+
+            if table_column:
+                sa_column = table_column.sqla_col
+
             sa_metric = self.sqla_aggregations[metric.get('aggregate')](sa_column)
             sa_metric = sa_metric.label(metric.get('label'))
             return sa_metric
@@ -518,7 +532,7 @@ def get_sqla_query(  # sqla
         metrics_exprs = []
         for m in metrics:
             if utils.is_adhoc_metric(m):
-                metrics_exprs.append(self.adhoc_metric_to_sa(m))
+                metrics_exprs.append(self.adhoc_metric_to_sa(m, cols))
             elif m in metrics_dict:
                 metrics_exprs.append(metrics_dict.get(m).sqla_col)
             else: