You should now make web global. Imagine two requests arrive more or less at
the time time. Both call connect? Now you have two threads using the same
global web object. You are back to the previous problem. This breaks
connection pooling, thread safety, etc.
You either call db = DAL() at each request and db is a local variable of
the request (which you call web) or you call db once in your model and use
db.reconnect() to duplicate the connection in the thread that is using it
(experimental).
On Monday, 10 December 2012 10:49:40 UTC-6, simon wrote:
>
> OK. I think I have done something similar to your suggestion. It seems to
> work but not sure about memory leaks. Also I note there is no web2py method
> to close a database connection.
>
> I want to put all the code interfacing to a 3rd party system in a single
> file. In that way if I change to a different 3rd party package I just need
> to change the one file.
>
> MODULE:
>
> MODEL:
> import ocart2
> web=ocart2.connect()
> rows=web(web.category.category_id>0).select()
> log.info((web.tables, rows))
>
> MODULE:
> web=None
>
> def connect():
> global web
> web=DAL(webstring, pool_size=10, migrate=False, migrate_enabled=False)
> web.define_table('category',
> Field('category_id', 'id', notnull=True, writable=False),
> Field('parent_id', 'integer', default=0, notnull=True,
> writable=False),
> Field('status', 'integer', default=1),
> Field('top', 'integer', notnull=True, writable=False))
> return web
>
>
>
>
>
> On Monday, 10 December 2012 15:39:34 UTC, Massimo Di Pierro wrote:
>>
>> You cannot do this. The connection has to be stablished in the models and
>> the tables have to be defined in the models as well.
>>
>> The issue is that a db connection only lives within a thread. Since
>> web2py is multithreaded at every request you may get a different thread.
>>
>> If is ok to do
>>
>> import ocart2
>> web=ocart2.web()
>> rows=web(web.category.category_id>0).select()
>> log.info((web.tables, rows))
>>
>> MODULE:
>> from gluon import *
>> from config import webstring
>> def web():
>> db = DAL(webstring, pool_size=10, migrate=False, migrate_enabled=False)
>> db.define_table('category',
>> Field('category_id', 'id', notnull=True, writable=False),
>> Field('parent_id', 'integer', default=0, notnull=True,
>> writable=False),
>> Field('status', 'integer', default=1),
>> Field('top', 'integer', notnull=True, writable=False))
>> return db
>>
>> You may also be able to do this:
>>
>> MODEL:
>>
>> import ocart2
>> web=ocart2.web
>> web.reconnect() # <<<
>> rows=web(web.category.category_id>0).select()
>> log.info((web.tables, rows))
>>
>> MODULE:
>> from gluon import *
>> from config import webstring
>> web=DAL(webstring, pool_size=10, migrate=False, migrate_enabled=False)
>> web.define_table('category',
>> Field('category_id', 'id', notnull=True, writable=False),
>> Field('parent_id', 'integer', default=0, notnull=True,
>> writable=False),
>> Field('status', 'integer', default=1),
>> Field('top', 'integer', notnull=True, writable=False))
>>
>> Yet the reconnect() method is experimental and I am not sure it does not
>> cause a memory leak. Yet you can help me test it.
>>
>> On Monday, 10 December 2012 04:13:43 UTC-6, simon wrote:
>>>
>>> In my model file I am importing a database definition from a module file.
>>> This works correctly the first time after the server is started showing
>>> the tablename and 11 rows in the table.
>>> However for the second and subsequent requests it shows a rows object
>>> but 0 rows in the table.
>>> It works fine if I put the model definition code inline rather than
>>> importing.
>>>
>>> [EDIT: I am fairly sure this used to work. Has something changed? Is
>>> there a way to get this to work?]
>>>
>>> MODEL:
>>>
>>> import ocart2
>>> web=ocart2.web
>>> rows=web(web.category.category_id>0).select()
>>> log.info((web.tables, rows))
>>>
>>> MODULE:
>>> from gluon import *
>>> from config import webstring
>>> web=DAL(webstring, pool_size=10, migrate=False, migrate_enabled=False)
>>> web.define_table('category',
>>> Field('category_id', 'id', notnull=True, writable=False),
>>> Field('parent_id', 'integer', default=0, notnull=True,
>>> writable=False),
>>> Field('status', 'integer', default=1),
>>> Field('top', 'integer', notnull=True, writable=False))
>>>
>>>
--
