Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
> > Maybe I'm misunderstanding you but if a foreignkey points to an object > > that is deleted, the object that refers to the deleted object will not > > be: > >This has nothing with RelatedJoin. You case is much simpler to fix: > > > > class building( SQLObject ): > > city = ForeignKey( 'city' ) > > city = ForeignKey( 'city' , cascade=True) Thanks a lot, this is really great, I didn't know about the cascade option, I was always overriding destroySelf. And of course you are right, this is specific to MultipleJoin and the OP was talking about RelatedJoin. Thanks again. - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ sqlobject-discuss mailing list sqlobject-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss
Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
On Tue, Jul 10, 2007 at 11:06:17AM +0200, Daniel Nogradi wrote: > Maybe I'm misunderstanding you but if a foreignkey points to an object > that is deleted, the object that refers to the deleted object will not > be: This has nothing with RelatedJoin. You case is much simpler to fix: > class building( SQLObject ): > city = ForeignKey( 'city' ) city = ForeignKey( 'city' , cascade=True) Oleg. -- Oleg Broytmannhttp://phd.pp.ru/[EMAIL PROTECTED] Programmers don't die, they just GOSUB without RETURN. - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ sqlobject-discuss mailing list sqlobject-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss
Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
> > Yes, you need to delete everything manually that is referenced by > > anything that is to be deleted. > >No, you don't. .destroySelf() in SQLObject 0.7.2 was extended to > automatically remove rows from the intermediate table. Does it work? Maybe I'm misunderstanding you but if a foreignkey points to an object that is deleted, the object that refers to the deleted object will not be: from sqlobject import * sqlhub.processConnection = connectionForURI( 'sqlite:/:memory:' ) class city( SQLObject ): buildings = MultipleJoin( 'building' ) class building( SQLObject ): city = ForeignKey( 'city' ) city.createTable( ) building.createTable( ) c = city( ) b1 = building( city=c ) b2 = building( city=c ) c.destroySelf( ) print building.select( ).count( ) print b1.city This will print 2 and then an SQLObjectNotFound exception will be raised so you need to manually delete all buildings that refer to a deleted city. I guess you had RelatedJoin in mind. - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ sqlobject-discuss mailing list sqlobject-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss
Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
Excellent. I tried changing syntax first, which didn't work, and then realized that the version of sqlobject installed on this machine was stale. I'm glad they are equivalent, because I enjoy terseness. Filing an upgrade bugrequest for the ubuntu people is now on my todo list. With the popularity of turbogears, a lot of folks are going to try a related join and then reach this problem. -- Jon On 7/9/07, Oleg Broytmann <[EMAIL PROTECTED]> wrote: > On Mon, Jul 09, 2007 at 08:28:51AM -0400, Jon R. Fox wrote: > > I switched to > > > > WebTag.get(tag_id_to_delete).destroySelf() > >This is equivalent to > > WebTag.delete(tag_id_to_delete) > > Oleg. > -- > Oleg Broytmannhttp://phd.pp.ru/[EMAIL PROTECTED] >Programmers don't die, they just GOSUB without RETURN. > > - > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > ___ > sqlobject-discuss mailing list > sqlobject-discuss@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss > -- Dr. Jon R. Fox Applied Physicist and Technologist [EMAIL PROTECTED] http://www.drfox.com 1-973-494-0370 - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ sqlobject-discuss mailing list sqlobject-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss
Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
On Mon, Jul 09, 2007 at 08:28:51AM -0400, Jon R. Fox wrote: > I switched to > > WebTag.get(tag_id_to_delete).destroySelf() This is equivalent to WebTag.delete(tag_id_to_delete) Oleg. -- Oleg Broytmannhttp://phd.pp.ru/[EMAIL PROTECTED] Programmers don't die, they just GOSUB without RETURN. - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ sqlobject-discuss mailing list sqlobject-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss
Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
On 7/9/07, Oleg Broytmann <[EMAIL PROTECTED]> wrote: > On Mon, Jul 09, 2007 at 12:09:25PM +0200, Daniel Nogradi wrote: > > Yes, you need to delete everything manually that is referenced by > > anything that is to be deleted. > >No, you don't. .destroySelf() in SQLObject 0.7.2 was extended to > automatically remove rows from the intermediate table. Does it work? I switched to WebTag.get(tag_id_to_delete).destroySelf() and that works great in SQLObject-0.10dev_r2730 that the python easy_install upgrade leads to. Unfortunately Ubuntu Feisty Fawn is still stuck on 0.7.1 on their distro. Best Regards, Jon - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ sqlobject-discuss mailing list sqlobject-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss
Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
On Mon, Jul 09, 2007 at 12:09:25PM +0200, Daniel Nogradi wrote: > Yes, you need to delete everything manually that is referenced by > anything that is to be deleted. No, you don't. .destroySelf() in SQLObject 0.7.2 was extended to automatically remove rows from the intermediate table. Does it work? Oleg. -- Oleg Broytmannhttp://phd.pp.ru/[EMAIL PROTECTED] Programmers don't die, they just GOSUB without RETURN. - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ sqlobject-discuss mailing list sqlobject-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss
Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
On Sat, Jul 07, 2007 at 02:34:11PM -0400, Jon R. Fox wrote: > What is the appropriate way to delete an instance of a WebTopic or a > WebTag so that RelatedJoin won't be broken? .destroySelf() in SQLObject 0.7.2 was extended to automatical remove rows from the intermediate table. Does it work? Oleg. -- Oleg Broytmannhttp://phd.pp.ru/[EMAIL PROTECTED] Programmers don't die, they just GOSUB without RETURN. - This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ ___ sqlobject-discuss mailing list sqlobject-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlobject-discuss
Re: [SQLObject] The proper way to delete an instance of an SQLObject that is linked as a RelatedJoin
> I have two simple SQLObject classes, WebTag and WebTopic that are
> related using a RelatedJoin:
>
>
> class WebTag(SQLObject):
> Name = StringCol( alternateID=True)
> Topics = RelatedJoin('WebTopic')
>
> class WebTopic(SQLObject):
> Name = StringCol( unique=True )
> Format = StringCol( default="rst" )
> Title = StringCol( )
> Subtitle = StringCol( default=None)
> Description = StringCol(default=None)
> Keywords = StringCol( default=None )
> Author = StringCol( default=None )
> DateTimePosted = DateTimeCol()
> DateTimeLastModified = DateTimeCol()
> UUID = StringCol()
> Content = StringCol( default=None )
> Tags = RelatedJoin('WebTag')
>
> What is the appropriate way to delete an instance of a WebTopic or a
> WebTag so that RelatedJoin won't be broken?
>
> Right now I have a simple:
>
> WebTopic.delete(id_to_delete)
>
> or a
>
> WebTag.delete(id_to_delete)
>
> But I just started getting this error, so I must have missed something
> in the documentation:
>
> >>> for a in WebTag.selectBy(Name='python'):
> ... print a.Name
> ... print a.Topics
> ...
> python
> Traceback (most recent call last):
> File "", line 3, in
> File "", line 1, in
> File "/usr/lib/python2.5/site-packages/sqlobject/joins.py", line
> 207, in performJoin
> return self._applyOrderBy([self.otherClass.get(id, conn) for (id,)
> in ids if id is not None], self.otherClass)
> File "/usr/lib/python2.5/site-packages/sqlobject/main.py", line 913, in
> get
> val._init(id, connection, selectResults)
> File "/usr/lib/python2.5/site-packages/sqlobject/main.py", line 958, in
> _init
> raise SQLObjectNotFound, "The object %s by the ID %s does not
> exist" % (self.__class__.__name__, self.id)
> sqlobject.main.SQLObjectNotFound: The object WebTopic by the ID 12
> does not exist
> >>>
>
> Any help and suggestions would be appreciated. The db can be wiped and
> started over, because this is a little test system. Should I have
> dropped all references to the missing WebTopic instance from all
> WebTag instances?
Yes, you need to delete everything manually that is referenced by
anything that is to be deleted.
A question to the experts: I usually do this by overloading
destroySelf so that it loops over all references, is that a good idea?
-
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