使用will_paginate和named_scoped

Question

我一直在使用分頁和命名範圍時遇到問題。 使用named_scope的第二頁或任何連續分頁頁面仍會返回第一頁的結果。 使用find（：all）可以正確返回分頁結果。 有沒有人能夠正確使用它們或遇到同樣的問題？

class Study < ActiveRecord::Base 
    named_scope :opened, :conditions => {:study_stat => [205, 11203]} 
end 

#find(:all) returns correct studies for both pages 
Study.find(:all, :conditions => {:study_stat => [205, 11203]}).paginate(:per_page => 10, :page => 1).each {|e| pp e.study_number } 
Study.find(:all, :conditions => {:study_stat => [205, 11203]}).paginate(:per_page => 10, :page => 2).each {|e| pp e.study_number } 

#using named_scope returns correct result for the first page but the second page has the same studies as ones in the page one. 
Study.opened.paginate(:per_page => 10, :page => 1).each {|e| pp e.study_number } 
Study.opened.paginate(:per_page => 10, :page => 2).each {|e| pp e.study_number } 

Answer 1

嘗試在您的paginate調用named_scope中包含：all選項。我記得前一段時間有類似的問題，並且爲我解決了這個問題。

所以，與其

Study.opened.paginate(:per_page => 10, :page => 2) 

嘗試

Study.opened.paginate(:all, :per_page => 10, :page => 2) 

Answer 2

我找到了原因。如rdoc 中所述，必須使用：order參數才能使分頁正常工作。對於named_scope尤其如此。 （我使用SQL Server 2005）

User.active.paginate(:all, :per_page => 5, :page => 1, :order=>'id').each {|e| pp e.user_name } 

User.active.paginate(:all, :per_page => 5, :page => 2, :order=>'id').each {|e| pp e.user_name }