test_sql.py 文件源码

def test_datetime_NaT(self):
        df = DataFrame({'A': date_range('2013-01-01 09:00:00', periods=3),
                        'B': np.arange(3.0)})
        df.loc[1, 'A'] = np.nan
        df.to_sql('test_datetime', self.conn, index=False)

        # with read_table -> type information from schema used
        result = sql.read_sql_table('test_datetime', self.conn)
        tm.assert_frame_equal(result, df)

        # with read_sql -> no type information -> sqlite has no native
        result = sql.read_sql_query('SELECT * FROM test_datetime', self.conn)
        if self.flavor == 'sqlite':
            self.assertTrue(isinstance(result.loc[0, 'A'], string_types))
            result['A'] = to_datetime(result['A'], errors='coerce')
            tm.assert_frame_equal(result, df)
        else:
            tm.assert_frame_equal(result, df)