It seems like your issue is that a query is executing and you are expecting a
certain result, but you are not getting it. So there's not a lot of relevant
detail here for someone that doesn't have your application open in front of
them (test data, exact code that produces query, illustration of expected
result row not present, extraneous stack traces regarding pagination logic and
secondary side effects like '"NoneType" has no attribute "groups"' removed).
So on your end, turn on echo ='debug', ensure the expected rows are returned
from the statement as it executes, and keep in mind an ORM query against a
single entity, i.e. session.query(Source).filter(...), will only return a
Source object if a primary key for Source is fully present in the row.
On Feb 9, 2011, at 5:21 AM, dalia wrote:
> Hi,
>
> I'm very new to sql alchemy..want help in debugging my code. I'm
> writing a web application using pylons, formalchemy and sqlalchemy.
> The issue is as follows -
>
> I've 2 tables namely source and pstn. i've declared them as follows -
>
> class Source(Base):
> __tablename__ = 'source'
> id = Column(Integer, primary_key=True)
> sh_code = Column(Integer, nullable=False)
> pstn_no = Column(Integer)
> details = Column(Text(), nullable=False)
> active = Column(Boolean, default=True)
>
> class PSTN(Base):
> __tablename__ = 'pstn'
> id = Column(Integer, primary_key=True)
> prev_no = Column(Integer)
> latest_no = Column(Integer, nullable=False)
> last_con = Column(Date())
> expiry_code = Column(Text())
> active = Column(Boolean, default=True)
>
> now i've joined the two tables to create a view namely History like
> this -
>
> pstn_table = PSTN.__table__
> source_table = Source.__table__
>
> j = join(pstn_table, source_table, pstn_table.c.latest_no ==
> source_table.c.pstn_no)
>
> class History(Base):
> __table__ = j
>
> in my admincontroller, i've set up the code so that whenever a new
> entry is added to 'source', the same 'pstn_no' would be inserted to
> 'pstn' table's 'latest_no' column. This piece is working fine and
> whenever i try to access class History from the grid, it loads all
> fine. The underlying sql query for the join is like this -
>
> SELECT pstn.id AS pstn_id, source.id AS source_id, pstn.prev_no AS
> pstn_prev_no, pstn.latest_no AS pstn_latest_no, pstn.last_con AS
> pstn_last_con, pstn.expiry_code AS pstn_expiry_code, pstn.active AS
> pstn_active, source.active AS source_active, source.sh_code AS
> source_sh_code, source.pstn_no AS source_pstn_no, source.details AS
> source_details
> FROM pstn JOIN source ON pstn.latest_no = source.pstn_no
> WHERE pstn.active = ?
> LIMIT 3 OFFSET 0
> 10:05:13,089 INFO [sqlalchemy.engine.base.Engine.0x...f490] (True,)
>
> Now, the problem is, if I manually add some entry into the 'pstn' and
> 'source' table where source.pstn_no = pstn.latest_no and try to access
> the History grid, the underlying sql remains the same but on the
> webpage, i get this error -
>
> ⇝ AttributeError: 'NoneType' object has no attribute 'groups'
> View as: Interactive (full) | Text (full) | XML (full)
> clear this
> clear this
> Module testapp.lib.admincontroller:292 in index view
> << def index(self, format='html', **kwargs):
> """REST api"""
> page = self.get_page()
> fs = self.get_grid()
> fs = fs.bind(instances=page)
>>> page = self.get_page()
> Module testapp.controllers.admin:45 in get_page view
> << options = dict(page=int(request.params.get('page', '1')))
> return Page(query,options)
>
> def hide(self, id):
>>> return Page(query,options)
> Module webhelpers.paginate:434 in __init__ view
> << self.items = self.collection
> else:
> self.items =
> list(self.collection[self.first_item-1:self.last_item])
>
> # Links to previous and next page
>>> self.items = list(self.collection[self.first_item-1:self.last_item])
> Module webhelpers.paginate:263 in __getitem__ view
> << if not isinstance(range, slice):
> raise Exception, "__getitem__ without slicing not
> supported"
> return self.obj[range]
>
> def __len__(self):
>>> return self.obj[range]
> Module sqlalchemy.orm.query:1528 in __getitem__ view
> << return list(res)[None:None:item.step]
> else:
> return list(res)
> else:
> return list(self[item:item+1])[0]
>>> return list(res)
> Module sqlalchemy.orm.query:1797 in instances view
> << process[0](row, rows)
> elif single_entity:
> rows = [process[0](row, None) for row in fetch]
> else:
> rows = [util.NamedTuple([proc(row, None) for
> proc in process],
>>> rows = [process[0](row, None) for row in fetch]
> Module sqlalchemy.orm.mapper:2275 in _instance view
> << instancekey=identitykey, isnew=isnew)
> is \
> EXT_CONTINUE:
> populate_state(state, dict_, row, isnew,
> only_load_props)
>
> else:
>>> populate_state(state, dict_, row, isnew, only_load_props)
> Module sqlalchemy.orm.mapper:2153 in populate_state view
> << for key, populator in populators:
> populator(state, dict_, row)
>
> session_identity_map = context.session.identity_map
>>> populator(state, dict_, row)
> Module sqlalchemy.orm.strategies:129 in new_execute view
> << if col is not None and col in row:
> def new_execute(state, dict_, row):
> dict_[key] = row[col]
> return new_execute, None, None
> else:
>>> dict_[key] = row[col]
> Module sqlalchemy.engine.base:2023 in __getitem__ view
> << "try 'use_labels' option on select
> statement." % key)
> if processor is not None:
> return processor(self._row[index])
> else:
> return self._row[index]
>>> return processor(self._row[index])
> Module sqlalchemy.processors:26 in process view
> << return None
> else:
> return type_(*map(int, rmatch(value).groups(0)))
> return process
>>> return type_(*map(int, rmatch(value).groups(0)))
> AttributeError: 'NoneType' object has no attribute 'groups'
>
> when i run the same sql query into my database, it returns me desired
> rows and all works fine. It's just that when i try to access the
> joined view grid from the webpage, this error shows up...any help???
>
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