Re: [SQLObject] Re: Preparing for 0.6.1

[Ian B. <ia...@co...>]

Luke Opperman wrote:
> Quoting Oleg Broytmann <ph...@ph...>:
> 
>> On Fri, Dec 31, 2004 at 11:05:41AM -0200, Carlos Ribeiro wrote:
>>
>>> > conn = connectionForURI("...")
>>> > if connection.supportTransactions:
>>> >    conn = conn.transaction()
>>> >
>>> > class Person(SQLObject):
>>> >    _connection = conn
>>>
>>    Neither. You can call conn.begin(), conn.commit() and conn.rollback()
>> at your will. After calling conn.rollback() you have to call
>> conn.begin(). That's simple.
> 
> 
> Am I correct in thinking this is unusable in a multi-threaded 
> environment, like
> Webware? The Person class shares one underlying connection to the database
> (pool is bypassed by Transaction), so if I have two interleaved requests 
> to an
> UpdateUser process (whether for different user records or not) they will 
> both
> try to begin(), and when one commits the other's changes up to that 
> point go
> along, or a rollback in one ends the transaction for the other?

It's compatible with threads, you just have to pass the connection in 
anytime it might be ambiguous what transaction you are working in (i.e., 
whenever you are dealing with class methods).  Though I'm curious what 
people do in Zope 3, if there's anything special in sqlo... there 
transactions are often per-thread (which is actually a lot more 
convenient, since you don't have to pass the connection around, and 
usually what you really want anyway).

-- 
Ian Bicking  /  ia...@co...  / http://blog.ianbicking.org