I am getting a better understanding...
But I don't quite get this stuff.
Attached in the controller.
I think I am close with it. But it seems to display all tags from all
users or something like that. (Very confused if you can't tell.)
I see the ._select( but I haven't a clue how it works, I did read it in
the manual, but still don't get it. :(
You may PM me if you thinkit would be better. I have skype as well.
---
Best Regards,
Jason Brower
On Sat, 2010-05-29 at 16:09 -0700, howesc wrote:
> Jason,
>
> the python stuff and sql ninja stuff are the results of some great
> code-reviewers teaching me tricks and lots of complex queries over the
> years!
>
> tags = db(db.concert_tag.playlist== \
> active_playlist.id).select(db.concert_tag.tag)
>
> that's a simple web2py query. i take you can follow that line.
>
> count = db.concert_tag.id.count()
> sum = db.concert_tag.magnitude.sum()
>
> count and sum come from the book. search on count and sum to find
> them.
>
> [t.tag for t in tags]
>
> is python magic. tags is the iterable query result. and that's a
> shortcut to build a list based on the iterable set. it is equivalent
> to:
> a = []
> for t in tags:
> a.append(t.tag)
>
> then,
> query = db((db.concert_tag.tag.belongs([t.tag for t in tags])) &
> (db.concert_tag.playlist != active_playlist.id) &
> (db.playlist.id == db.concert_tag.playlist) )
> is the query, with the "magic" list for the belongs operator (just
> like SQL "IN" clause). so this gets all concert_tags and associated
> playlists (except for the active playlist) with one or more tag in
> common with the active playlist - because the tag list in the belongs
> is the list of tags for the active playlist.
>
> rows = query.select(db.playlist.name,
> db.concert_tag.playlist,
> db.playlist.uid,
> count,
> sum,
> groupby=db.concert_tag.playlist|
> db.playlist.name|
> db.playlist.uid,
> orderby=~count|~sum|~db.playlist.date,
> limitby=(0,NUM_RELATED_LINKS))
>
> the select statement. determines what fields to get - playlist.name,
> playlist.uid, count of shared tags, sum of the magnitude of the shared
> tags (in your system we can assume all magnitudes are 1 so this part
> is unnecessary). I messed up the group by in my first email because
> it should contain all fields selected except for the count and sum
> fields (the aggregate fields). lookup how SQL count/sum/group by work
> if you need more information. orderby is just count (desc), sum
> (desc), and playlist.date (desc) applied in order (lookup SQL order
> by for more information). Limitby gets me NUM_RELATED_LINKS (which is
> a constant of 5 for me) rows, starting from the first row returned.
>
> does that help more?
>
> cfh
>
>
>
> On May 29, 4:03 am, Jason Brower <[email protected]> wrote:
> > Perhaps if you broke it down a bit I could get what is going on. For
> > example, it looks like some pretty cool python syntax with.
> > [t.tag for t in tags] I really can't understand what that does but it
> > looks cool. :P
> > I also didn't know you could use or operators in the limitby, spiffy.
> > Thanks for your help so far. :)
> > Best Regards,
> > Jason
> >
> > On Fri, 2010-05-28 at 14:32 -0700, howesc wrote:
> > > check outwww.tenthrow.com, click on a concert and you will see an
> > > "other concerts" box. those are generated following several rules,
> > > the first if finding concerts that share tags with this concert. My
> > > tags have a "magnitude" or a weighting, so some are more valued than
> > > others. hence the magnitude references below. otherwise my tag and
> > > concert_tag tables mimic what you have in your model. I don't display
> > > the tag name that they share though.
> >
> > > my relevant queries:
> > > #active_playlist is a record, passed to my function.
> > > tags = db(db.concert_tag.playlist== \
> >
> > > active_playlist.id).select(db.concert_tag.tag)
> >
> > > count = db.concert_tag.id.count()
> > > sum = db.concert_tag.magnitude.sum()
> > > query = db((db.concert_tag.tag.belongs([t.tag for t in tags]))
> > > &
> > > (db.concert_tag.playlist != active_playlist.id) &
> > > (db.playlist.id == db.concert_tag.playlist) )
> >
> > > rows = query.select(db.playlist.name,
> > > db.concert_tag.playlist,
> > > db.playlist.uid,
> > > count,
> > > sum,
> > > groupby=db.concert_tag.playlist|
> > > db.playlist.uid,
> > > orderby=~count|~sum|~db.playlist.date,
> > > limitby=(0,NUM_RELATED_LINKS))
> >
> > > dunno if that helps or not...
> >
> > > On May 28, 1:31 pm, Jason Brower <[email protected]> wrote:
> > > > I tried doing this last year and I was close and couldn't figure it out.
> > > > I need to complete implementing it and wondered if you could help out.
> > > > Using the attatched model I want to do the following:
> > > > I need to have a list of all the users that have similar tags to the
> > > > user that is logged in. I need those tag names as well.
> > > > As an added sugar candy bonus I wonder if there is an easy way to could
> > > > them or should I just count them as I sort throw them in the view.
> > > > I think I am close with this, it modified from something done last year.
> > > > Am I doing this right?
> > > > Best Regards,
> > > > Jason Brower
> >
> > > > My pertinent controller function:
> > > > ---
> >
> > > > @auth.requires_login()
> > > > def your_connections():
> > > > related_tags = db((
> >
> > > > db.auth_user.id==db.user_tags.user_id)&(db.user_tags.tag_id==db.tag.id)&(db.user_tags.tag_id.belongs(
> > > > db(db.user_tags.user_id==auth.user.id)._select(
> > > > db.user_tags.tag_id)))).select(
> > > > db.auth_user.ALL,db.tag.ALL,groupby=db.auth_user.id)
> > > > return dict(related_tags = related_tags)
> > > > ---
> >
> > > > db.py
> > > > 3KViewDownload
#!/usr/bin/python
@auth.requires_login()
def your_connections():
tags_user_id =(auth.user.id==db.user_tags.user_id) #get all the tags user data
user_ids_tag = (db.user_tags.tag_id==db.tag.id) #get all the users tag data
users_tags = (db.user_tags.user_id==auth.user.id) #get all the users tags
related_tags = db(tags_user_id & user_ids_tag &
(db.user_tags.tag_id.belongs(db(users_tags)._select(db.user_tags.tag_id)))).select(db.auth_user.ALL,db.tag.ALL, orderby=db.auth_user.id)
#if db.user_tags IN user's tags ???? What is all this stuff about? I am sure this is the magic ??????????????? Sort by the different users ids
''''
current_user = None
tag_count = 0
tag_counts = {}
for tag in related_tags:
if current_user != tag.auth_user.id:
current_user = tag.auth_user.id
tag_count = 0
else:
tag_count += 1
tag_counts[tag.auth_user.nickname]=[tag_count, tag.auth_user.avatar, tag.auth_user.id]
'''
tag_counts = {}
return dict(tag_counts = tag_counts, related_tags = related_tags)
