TypeError when running a 'COPY' command on Postgres
Thanks for the excellent bug report.  I think I need to clarify the docs a bit -- `RawQuery` was meant to be used for expressing `SELECT` statements.  RawQuery is there to give you a way to specify any select statement and _return model instances_.

If you just want to execute some plain old SQL, try:

``` python

# assume somewhere you have a db defined
database = PostgresqlDatabase('something')

# ... later ...
sql = "COPY uk_towns FROM '{}' DELIMITERS ',' CSV HEADER".format(towns_file)
res = database.execute_sql(sql)
```
 Grand - thanks for the clarification - its abit if an edge case. As I said before I lurrrrve Peewee Thanks !! :)) 
 Thanks!  So glad to hear that.  I'm pushing an update to the docs in a few moments that should hopefully clear this up for the next person who runs into it.

I'm loading a CSV file on Postgres using the COPY command, and get a TypeError (I think its because the COPY command returns None).

Here's the code:

``` python
def seed_towns():
    print "Seeding Towns tables..."
    towns_file = os.path.join(os.path.abspath(os.curdir), 'data/uk-towns-list/uk-towns.csv')
    Town.drop_table(fail_silently=True)
    Town.create_table(fail_silently=True)
    print "Loading data..."
    rq = RawQuery(Town, "COPY uk_towns FROM '{}' DELIMITERS ',' CSV HEADER".format(towns_file))
    try:
        rq.execute()
        # Wierdness here
   except TypeError, e:
        assert Town.select().count() == 43143
    finally:
        print 'Done.'
```

And here's the trace:

``` python
Traceback (most recent call last):
  File "./manage.py", line 45, in <module>
    manager.run()
  File "/Users/ben/repos/badbatch/lib/python2.7/site-packages/flask_script/__init__.py", line 351, in run
    result = self.handle(sys.argv[0], command, sys.argv[2:])
  File "/Users/ben/repos/badbatch/lib/python2.7/site-packages/flask_script/__init__.py", line 324, in handle
    return command.handle(app, *positional_args, **command_namespace.__dict__)
  File "/Users/ben/repos/badbatch/lib/python2.7/site-packages/flask_script/commands.py", line 143, in handle
    return self.run(*args, **kwargs)
  File "./manage.py", line 31, in seed_towns
    for obj in rq.execute():
  File "/Users/ben/repos/badbatch/lib/python2.7/site-packages/peewee.py", line 1365, in execute
    self._qr = ResultWrapper(self.model_class, self._execute(), None)
  File "/Users/ben/repos/badbatch/lib/python2.7/site-packages/peewee.py", line 1090, in __init__
    for i in range(len(self.cursor.description)):
TypeError: object of type 'NoneType' has no len()
```
