Add fix for pyodbc+mssql (#6621)

* add fix for odbc+mssql

* fix for pylint/pep8

tests/core_tests.py

@@ -19,12 +19,14 @@ import sqlalchemy as sqla
 from superset import dataframe, db, jinja_context, security_manager, sql_lab
 from superset.connectors.sqla.models import SqlaTable
 from superset.db_engine_specs import BaseEngineSpec
+from superset.db_engine_specs import MssqlEngineSpec
 from superset.models import core as models
 from superset.models.sql_lab import Query
 from superset.utils import core as utils
 from superset.utils.core import get_main_database
 from superset.views.core import DatabaseView
 from .base_tests import SupersetTestCase
+from .fixtures.pyodbcRow import Row
 
 
 class CoreTests(SupersetTestCase):
@@ -673,6 +675,36 @@ class CoreTests(SupersetTestCase):
             {'data': pd.Timestamp('2017-11-18 22:06:30.061810+0100', tz=tz)},
         )
 
+    def test_mssql_engine_spec_pymssql(self):
+        # Test for case when tuple is returned (pymssql)
+        data = [(1, 1, datetime.datetime(2017, 10, 19, 23, 39, 16, 660000)),
+                (2, 2, datetime.datetime(2018, 10, 19, 23, 39, 16, 660000))]
+        df = dataframe.SupersetDataFrame(
+            list(data),
+            [['col1'], ['col2'], ['col3']],
+            MssqlEngineSpec)
+        data = df.data
+        self.assertEqual(len(data), 2)
+        self.assertEqual(data[0],
+                         {'col1': 1,
+                          'col2': 1,
+                          'col3': pd.Timestamp('2017-10-19 23:39:16.660000')})
+
+    def test_mssql_engine_spec_odbc(self):
+        # Test for case when pyodbc.Row is returned (msodbc driver)
+        data = [Row((1, 1, datetime.datetime(2017, 10, 19, 23, 39, 16, 660000))),
+                Row((2, 2, datetime.datetime(2018, 10, 19, 23, 39, 16, 660000)))]
+        df = dataframe.SupersetDataFrame(
+            list(data),
+            [['col1'], ['col2'], ['col3']],
+            MssqlEngineSpec)
+        data = df.data
+        self.assertEqual(len(data), 2)
+        self.assertEqual(data[0],
+                         {'col1': 1,
+                          'col2': 1,
+                          'col3': pd.Timestamp('2017-10-19 23:39:16.660000')})
+
     def test_comments_in_sqlatable_query(self):
         clean_query = "SELECT '/* val 1 */' as c1, '-- val 2' as c2 FROM tbl"
         commented_query = '/* comment 1 */' + clean_query + '-- comment 2'

tests/fixtures/pyodbcRow.py

@@ -0,0 +1,12 @@
+# pylint: disable=C,R,W
+
+
+class Row(object):
+    def __init__(self, values):
+        self.values = values
+
+    def __name__(self):
+        return 'Row'
+
+    def __iter__(self):
+        return (item for item in self.values)