"Adapter does not support geometry" exception when declaring geometry field - sqlite

Question

In my application, an "Adapter does not support geometry" exception is being thrown when attempting to create a field of type, "geometry()". For my test application, I'm using an sqlite DB (production will use postgres):
db = DAL('sqlite://storage.sqlite', pool_size = 1, fake_migrate_all= False)
The DB table in question is declared within a class, inside of a module, and contains a several fields, some of which contain location data:
from gluon.dal import Field, geoPoint, geoLine, geoPolygon
class Info(Base_Model):
def __init__(...):
try:
db.define_table('t_info',
...
Field('f_geolocation', type='geometry()',
label = current.T('Geolocation')),
Field('f_city', type='string',
label = current.T('City')),
...
except Exception as e:
...
Edit:
As per Anthony's suggestion, I've modified the DAL constructor call to the following:
db = DAL('spatialite://storage.sqlite', pool_size = 1)
It produces the following error message:
Traceback (most recent call last):
File "C:\...\web2py\gluon\restricted.py", line 227, in restricted
exec ccode in environment
File "C:/My_Stuff/Programs/web2py/applications/Proj/models/db.py", line 38, in <module>
db = DAL('spatialite://storage.sqlite', pool_size = 1)
File "C:\...\web2py\gluon\packages\dal\pydal\base.py", line 171, in __call__
obj = super(MetaDAL, cls).__call__(*args, **kwargs)
File "C:\...\web2py\gluon\packages\dal\pydal\base.py", line 457, in __init__
raise RuntimeError("Failure to connect, tried %d times:\n%s" % (attempts, tb))
RuntimeError: Failure to connect, tried 5 times:
Traceback (most recent call last):
File "C:\...\web2py\gluon\packages\dal\pydal\base.py", line 435, in __init__
self._adapter = ADAPTERS[self._dbname](**kwargs)
File "C:\...\web2py\gluon\packages\dal\pydal\adapters\base.py", line 53, in __call__
obj = super(AdapterMeta, cls).__call__(*args, **kwargs)
File "C:\...\web2py\gluon\packages\dal\pydal\adapters\sqlite.py", line 169, in __init__
if do_connect: self.reconnect()
File "C:\...\web2py\gluon\packages\dal\pydal\connection.py", line 129, in reconnect
self.after_connection_hook()
File "C:\...\web2py\gluon\packages\dal\pydal\connection.py", line 81, in after_connection_hook
self.after_connection()
File "C:\...\web2py\gluon\packages\dal\pydal\adapters\sqlite.py", line 177, in after_connection
self.execute(r'SELECT load_extension("%s");' % libspatialite)
File "C:\...\web2py\gluon\packages\dal\pydal\adapters\base.py", line 1326, in execute
return self.log_execute(*a, **b)
File "C:\...\web2py\gluon\packages\dal\pydal\adapters\base.py", line 1320, in log_execute
ret = self.cursor.execute(command, *a[1:], **b)
OperationalError: The specified module could not be found.

Answer 1

If you want to use geometry fields with SQLite, you must use the spatialite adapter, which makes use of the SpatialLite extension for SQLite:
db = DAL('spatialite://storage.sqlite', pool_size = 1)
Note, you must have spatialite installed for this to work.