On Thursday, June 9, 2011 8:16:28 PM UTC-6, joanne
wrote:>
> Hi, I am new in Rails, and now i have a problem to take data from more
> 4 tables in DB
>
> This is my code:
>
> //user model
> belongs_to season
> belongs_to album
> has_many albums
>
I''m assuming this *isn''t* a copy/paste since it should look
more like:
class User < ActiveRecord::Base
belongs_to :season
belongs_to :album
has_many :albums
# ...
>
> #### ----->
> def get_pic
>
> @pic = Picture.where(:album_id => ''Album.album_id'' ,
> user.where(:culture_id =>
''Culture.culture_id'')).first
>
> end
> ### ----->
>
Hmm, I''ll talk about this where later where you re-pasted it below
(regarding a syntax error)...
>
> // Picture model//
> belongs_to season
> belongs_to album
>
> //Culture model//
> has_many pictures
> has_one
>
>
Culture has_one what? It''s looking to me like you''re omitting
stuff?
>
> // album model//
> has_many pictures
> has_many pictures through => 2011year
> has_many pictures through => 2010year
> has_many pictures through => 2009year
>
I''m pretty sure this is trouble. Firstly, having multiple #has_many
calls,
all with the same relationship name (:pictures) would either fail or
subsequent calls would overwrite the prior calls'' relationship
metadata, or
other weirdness would ensue (no sure exactly which as I''ve never
tried).
What would it mean if I had an Album instance and I said:
"@album.pictures"?
Would I get the ones from the first #has_many, or the second, third, or
fourth?
Also, the :through option on #has_many implies you''ve got a
relationship to
the "through" model already. So, if you said: "has_many
:pictures, :through
=> :2009year" that would require you to already have a "has_many
:2009year"
above it (or something like that, not really sure what you''re trying to
do).
>
> //2011yea model //
> belongs_to picture
>
> //2010yea model //
> belongs_to picture
>
> //2009yea model //
> belongs_to picture
>
>
Yes, but do they "#belong_to :album" too? (Also required for the
#has_many
:through calls in the section above).
> and i want to to take the image data from PICTURE table
>
> picture_id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
> album_id integer NOT NULL,
> culture_id integer NOT NULL,
> image binary
>
> my user controller is
>
> def show
> @user= User.all
>
Umm, you''re going to show "all" your users? You usually only
see this for
the "index" action...
> @my= User.get_pic
>
The code you had above defined #get_pic as a regular instance method on the
User model, not as a class method. I''d think you''d need
something like:
@user = User.find(params[:id])
@my = @user.get_pic
...but again, I can''t be sure (not enough info).
>
> end
>
> Please help.. i want stuck almost a week,. how i can i take a value
> in Picture table.
> Plus, i have caused a problem on this code as well
>
> @pic = Picture.where(:album_id => ''Album.album_id'' ,
> user.where(:culture_id =>
''Culture.culture_id'')).first
>
>
Yes, this is bad syntax. The #where class method call starts with you
passing an implicit ruby hash. Then, for the second hash entry, you say
"user.where(...)" which syntax doesn''t comprise a hash
"key => value" entry.
This is your basic syntax error. However, you''ve got many more problems
besides that. Your relationships ":album_id =>
''Album.album_id''" are weird
(very likely wrong). Are you trying to do a join in there? There is a
separate method for that.
> it causes a syntax error
>
>
> Please help . please help ... thanks thanks
> Thanks
Next time, you''ll get better info if you post actual code as
you''ve got it
in your files. You can omit irrelevant methods (if they''re not
referenced at
all by any of the code you *do* need help with). There are many other thing
that look problematic but I''ll just go with what I''ve
commented on here.
You mentioned that you''re new to rails. Often, a lot of rails newbies
are
also ruby newbies. I don''t know for a fact if this is true for you or
not,
but in general, the better your basic ruby knowledge, the better equipped
you''ll be for doing rails work.
So, I''d recommend brushing up on your ruby. Also, as others have
recommended
to people asking questions on this list, I''d recommend working through
the Rails
Tutorial <http://ruby.railstutorial.org/ruby-on-rails-tutorial-book>.
Either way, good luck solving your problems and learning rails.
--
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To view this discussion on the web visit
https://groups.google.com/d/msg/rubyonrails-talk/-/twsNjXo0vDoJ.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.