message: Use correct dialect for escaping functions.
  Column functions are currently escaped with the
  same dialect that is being used by Superset for its
  metadata storage.  Instead the dialect of the target
  table should be used when escaping column names.
diff: @@ -572,6 +572,7 @@ class SqlaTable(Model, BaseDatasource):
  M = SqlMetric # noqa
  metrics = []
  any_date_col = None
  + db_dialect = self.database.get_sqla_engine().dialect
  for col in table.columns:
  try:
  datatype = "{}".format(col.type).upper()
  @@ -603,7 +604,7 @@ class SqlaTable(Model, BaseDatasource):
  any_date_col = col.name
  quoted = "{}".format(
  - column(dbcol.column_name).compile(dialect=db.engine.dialect))
  + column(dbcol.column_name).compile(dialect=db_dialect))
  if dbcol.sum:
  metrics.append(M(
  metric_name='sum__' + dbcol.column_name,
  