If I merge the updated channel like you can see in this piece of code
it's working:
def insertXML(channels, strXml):
"""Insert a new channel given XML string"""
channel = Channel()
session = rdb.Session()
channel.fromXML(strXml)
fillChannelTemplate(channel, channels)
for item in channel.items:
if item.id == 0:
item.id = None
break
session.merge(channel)
for chan in channels:
if chan.id == channel.id:
chan.items.append(item)
break
My problem is I'm using channels, it's a list of channels which I save
it in HTTP session object. The channels list is a detached object
which I get using joinload option. So in this case, I update the
object correctly in database, but It isn't persistent in channels if I
do this:
for chan in channels:
if chan.id == channel.id:
chan.items.append(item)
break
Do you have any idea how I can solve this problem? or another
approach?
Thanks!
On Sep 10, 5:09 pm, Michael Bayer <[email protected]> wrote:
> On Sep 10, 2010, at 2:57 PM, Alvaro Reinoso wrote:
>
>
>
> > Hello guys,
>
> > I have this table:
>
> > class Channel(rdb.Model):
> > rdb.metadata(metadata)
> > rdb.tablename("channels")
>
> > id = Column("id", Integer, primary_key=True)
> > title = Column("title", String(100))
> > hash = Column("hash", String(50))
> > runtime = Column("runtime", Float)
>
> > items = relationship(MediaItem, secondary="channel_items",
> > order_by=MediaItem.position, backref="channels")
>
> > I have a list of channels, but they are detached objects. I get them
> > using joinedload option because I maniputale those objects sometimes.
> > When I do that, I update the object.
>
> > This time, I'm trying to add a new item to a detached channel object.
> > This is the code:
>
> > def insertXML(channels, strXml):
> > """Insert a new channel given XML string"""
> > channel = Channel()
> > session = rdb.Session()
> > result = ""
>
> > channel.fromXML(strXml)
> > fillChannelTemplate(channel, channels)
> > if channel.id == 0:
> > session.add(channel)
> > session.flush()
> > channels.append(channel)
> > else:
> > for chan in channels:
> > if chan.id == channel.id:
> > chan.runtime = channel.runtime
> > chan.modified = datetime.date.today()
>
> > for item in channel.items:
> > if item.id == 0:
> > chan.items.append(item)
>
> > session.merge(chan)
>
> > The item is inserted in the database, but It doesn't create the
> > relation in channel_items.
>
> > Besides, I get this error:
>
> > FlushError: New instance <Channel at 0xb75eeec> with identity key
> > (<class 'zeppelinlib.channel.ChannelTest.Channel'>, (152,)) conflicts
> > with persistent instance <Channel at 0xb598dec
>
> anytime you have that error you should be using merge() to merge state into
> that which is already existing, the return value from merge() is then what
> you need to use for your new state. I see you tried using merge earlier but
> your issue is not clear.
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