Problem with creating a database scheme/model

Hi there,

I have a problem with creating a database scheme and the according
models.
To describe the situation I made small scribble, because I think that
explains it best.

http://herrbuerger.com/scheme.001.jpg

So I have several pages and each page has many texts, pictures and
assets. So far the models look like this:

Page
has_many :texts
has_many :pictures
has_many :assets

Texts
belongs_to :page

Picture
belongs_to :page

Asset
belongs_to :page

Right now i have to query each table (pictures, texts, assets)
seperately to get all the stuff that belongs to ONE page.

What I want to do is just fire one query to get all the items. I
really rack my brain on this one.
Hopefully one of you guys can give me a hint on how to do this.

Thanks for your time,
Chris

(note: I posted this to the other Rails Mailinglist, because I did not
know about this one. However this list seems to be the more active
one.)

If I understand you correctly: Personally I’d do a find_by_sql with a
couple of joins in but I’m told you can use the acts_as_ferret plugin
too

Chris-Aix wrote:

Page
has_many :texts
has_many :pictures
has_many :assets

Texts
belongs_to :page

Picture
belongs_to :page

Asset
belongs_to :page

Right now i have to query each table (pictures, texts, assets)
seperately to get all the stuff that belongs to ONE page.

What I want to do is just fire one query to get all the items. I
really rack my brain on this one.
Hopefully one of you guys can give me a hint on how to do this.

p = Page.find :first
p.texts, p.pictures, p.assets

If you mean that rails has to make all the queries then search on eager
loading in the rails api

ok. i read the stuff about eager loading and it helped me out a little
bit.

right now i am doing something like this:
page = Page.find(:first, :include => [:pictures,:assets, :texts])

so this query gets all the results i need. the problem is each of this
tables has a position field and the endresult should be ordered this
way.
i made another scribble to explain it better.

http://herrbuerger.com/scribble_list.001.jpg

any ideas?

Thanks for your tips.

The first thing that came to my mind was find_by_sql, but I guess that
the queries are not that easy.
And, Ilan, the first solution that you recommended is like the one I
use now.

And to specify my problem a little bit more I’ll try to explain it a
little better.
Right now the (pseudo)code on the “page” looks like that:

get_all_texts
get_all_pictures
get_all_assets

The thing is that these elements should come out ordered, so it look
for example like this:

text_1
picture_2
asset_1
picture_1

I hope that explains it a little bit better.

On Jan 22, 10:54 pm, Ilan B. [email protected]

Chris-Aix wrote:

ok. i read the stuff about eager loading and it helped me out a little
bit.

right now i am doing something like this:
page = Page.find(:first, :include => [:pictures,:assets, :texts])

so this query gets all the results i need. the problem is each of this
tables has a position field and the endresult should be ordered this
way.
i made another scribble to explain it better.

http://herrbuerger.com/scribble_list.001.jpg

any ideas?

irb(main):001:0> elements = []
=> []
irb(main):002:0> 10.times {|n| elements << %w{text picture
asset}.sort_by {rand}.shift + "" + n.to_s}
=> 10
irb(main):003:0> elements.sort_by {rand}
=> [“picture_7”, “asset_5”, “text_3”, “text_6”, “picture_0”,
“picture_8”, “text_2”, “text_9”, “picture_4”, “text_1”]
irb(main):004:0> elements.sort_by {|a| a.match(/
(\d+)$/)[1].to_i}
=> [“picture_0”, “text_1”, “text_2”, “text_3”, “picture_4”, “asset_5”,
“text_6”, “picture_7”, “picture_8”, “text_9”]

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