Bug in paginating_find

rubyonrails-talk
1

Hi,

I juste found a bug in the plugin paginating_find. I order my records using an associated model column.

When i do that, record are beign sorted only based on those displayed on the page, and not based on all of the records found.

Is anyone experienced this problem ? does anyone see a solution ?

Thanks

2

Differenthink wrote:

Hi,

I juste found a bug in the plugin paginating_find. I order my records using an associated model column.

When i do that, record are beign sorted only based on those displayed on the page, and not based on all of the records found.

Is anyone experienced this problem ? does anyone see a solution ?

Thanks

Hi Differentthink,

Will you please post the related code? I had a problem not too long ago with try to sort on a secondary association, and I thought was a bug in associations, but it turned out to be a lack of understand on my part.

Peace, Phillip

3

Phillip Koebbe wrote:

Hi Differentthink,

Will you please post the related code? I had a problem not too long ago with try to sort on a secondary association, and I thought was a bug in associations, but it turned out to be a lack of understand on my part.

Peace, Phillip

Whew, you'd think that I never spoke/wrote English before.

First, I misspelled your name. Too many tees. Differenthink. Sorry.

Second, "try" should be "trying" in the second sentence.

Third, "...and I thought _it_ was a bug..."

Last (I think), "...lack of understand_ing_ on my part."

Peace, Phillip

4

No problem.

here is my piece of code :

@question = Question.find(:all, :conditions=>["systeme_id IN (?)", @systeme], :include=> :reponses, :order=>"reponses.date DESC", :page =>{ :size=>10, :current=>params[:page]})

My :order condition works, but only for records shown on the page by pagainting_find... it s why i guess for a bug in the plugin. (when i order by a common column of the record, there is no problem)

Any idea ?

5

Hi Differentthink. Can you post the sql query that is generated by paginating_find?

6

I ve a big clue !

the problem is not in the plugin, but in my order condition. Let me explain.

For each "question", i can have many "reponse". When i use : "reponses.date DESC" i want to order by the last "reponse"... and it seems it use the first one...

Any idea to make it understand to order by last "reponse" ?

Thanks a lot for everything,

7

Differenthink wrote:

I ve a big clue !

the problem is not in the plugin, but in my order condition. Let me explain.

For each "question", i can have many "reponse". When i use : "reponses.date DESC" i want to order by the last "reponse"... and it seems it use the first one...

Any idea to make it understand to order by last "reponse" ?

Thanks a lot for everything,

On 21 juin, 19:57, "alexkwo...@gmail.com" <alexkwo...@gmail.com>

I'm not sure I completely understand what it is you're trying to do. I *think* you're looking for two levels of sorting: question then response. What field on questions is a reasonable candidate for sorting? Name, description, order, id? Suppose you have a field on questions called sort_order, you could do something like

:order => 'questions.sort_order asc, responses.date desc'

If that's not what you're asking, either write me off as loony or explain it a bit more clearly.

Peace, Phillip

8

I want to order by the last "reponse" datetime. which should be : "responses.date desc"

but when doing that, it seems that it sorts by the first "reponse" found for a question and note the last "reponse" posted...

is it a bit clearer ? (think for it as a forum, where there is one "question" and could be many "answers" (=reponses)

9

I want to order by the last "reponse" datetime. which should be : "responses.date desc"

but when doing that, it seems that it sorts by the first "reponse" found for a question and note the last "reponse" posted...

so you want to order questions by the max of responses.date for each
question ?

Fred

10

Differenthink wrote:

I want to order by the last "reponse" datetime. which should be : "responses.date desc"

but when doing that, it seems that it sorts by the first "reponse" found for a question and note the last "reponse" posted...

is it a bit clearer ? (think for it as a forum, where there is one "question" and could be many "answers" (=reponses)

On 22 juin, 00:25, Phillip Koebbe <rails-mailing-l...@andreas-s.net>

Are you trying to display a list of questions according to which one has the most recent response? The finder that you posted earlier

@question = Question.find(:all, :conditions=>["systeme_id IN (?)", @systeme], :include=> :reponses, :order=>"reponses.date DESC", :page =>{ :size=>10, :current=>params[:page]})

is looking for all questions for the given systeme_ids, and will join to the responses table on each question. So your order clause is going to include all the multiple responses for each question. I'm not sure that's what you want. If you want to order the questions by the *most recent response* for each question, you will need to create an association such as

class ForumPost < ActiveRecord::Base   has_one :most_recent_response, :class_name => 'Response', :foreign_key => 'question_id', :order => 'date desc' end

Then in the finder, include that association

Question.find(:all, :include => :most_recent_response, :order => 'responses.date desc')

Something like that anyway. I'm using some code I wrote earlier this year using ForumPosts as a guide, but in my case, the most recent reply is also a ForumPost, so my association is a little more complicated. But I did something similar.

Oh, now that I look more at my code, I see that I constructed custom SQL to do the finding of replies, so this may not work like I think. Give it a try, though, and see what happens.

Peace, Phillip

11

Yes, this is exactly what i want to do : "If you want to order the questions by the *most recent response* for each question"

I ll give a try to your piece of code

thanks

12

class ForumPost < ActiveRecord::Base has_one :most_recent_response, :class_name =>
'Response', :foreign_key => 'question_id', :order => 'date desc' end

including has_ones like that doesn't really work (because of
how :include works under the scenes. there's not a nice way in sql (at
least not a portable one) to say join this table but give me only the
top row and things like that. One way round it would be to do something like select distinct questions.id from questions inner join responses on question_id = questions.id order by responses.date desc limit x (i'll leave it up to you to write this in AR speak)

this gives you the x question ids with most recent responses. You can
then load those questions & responses.

Fred

13

Hum... Ok so there is no good, nice, proper way to do this...

I think of adding a column "date_last_rep" on my 'question" model that i update each time there is an answer.... that way it will be easier to sort it :slight_smile:

14

Frederick Cheung wrote:

including has_ones like that doesn't really work (because of how :include works under the scenes. there's not a nice way in sql (at least not a portable one) to say join this table but give me only the top row and things like that.

You are, of course, correct again, Fred. That would explain why I created a custom SQL statement to do my searching.

Peace, Phillip