Null SQL Values in Frame Query causing TypeError
When I execute a io.sql.frame_query, and the one of the rows in a sql data column (just ints) is Null (SQL Server using FreeTDS), I get a type error when one of the frame functions tries to get the length of a NoneType object.

The reason I suspect it is due to a Null value is because when I change the query to be top X it works fine, until X includes a row that has a NULL Value

Traceback (most recent call last):
  File "/Users/kbrandt/src/Orionpy/test_script.py", line 4, in <module>
    ny_web01.applications.Socket_Server.components.SocketServer_exe.get_data()
  File "/Users/kbrandt/src/Orionpy/orion.py", line 159, in get_data
    Component.get_data(self, query_string, time_win)
  File "/Users/kbrandt/src/Orionpy/orion.py", line 144, in get_data
    self.data = psql.frame_query(query, self.node._connection)
  File "/Library/Python/2.7/site-packages/pandas/io/sql.py", line 146, in read_frame
    coerce_float=coerce_float)
  File "/Library/Python/2.7/site-packages/pandas/core/frame.py", line 846, in from_records
    coerce_float=coerce_float)
  File "/Library/Python/2.7/site-packages/pandas/core/frame.py", line 4957, in _to_sdict
    if len(data) == 0 or not data:
TypeError: object of type 'NoneType' has no len()
[Finished in 2.8s with exit code 1]
