Question

I realize that this could be a rare occurrence (that two or more users would have the same blog post title) but this is something my client wants so, I have to figure it out.

I have a query @blog_posts (which is a query on Posts that changes based on location, etc). I need a way to to list out all the posts titles and how many times that title occurs within the query @blog_posts

与此类似:

How to clean a car (2)
I love baseball (1)

是否有分类和分类的标准做法?

www.un.org/Depts/DGACM/index_spanish.htm 简言之,我需要计算一下问询中的出现情况: 编码>@blog_posts = 员额所在地(......)(例如)——不是所有现有员额。

Answer 1

Sounds like you basically want to count occurrences: this answer could be adapted to your purposes.

如果您在1.8.7或更新时考虑group_by:

ruby-1.9.2-p180 :002 > posts = ["How to clean a car", "How to clean a car", "I love baseball"]
 => ["How to clean a car", "How to clean a car", "I love baseball"]
ruby-1.9.2-p180 :007 > posts.group_by {|e| e}.map {|k, v| {k => v.length}}
 => [{"How to clean a car"=>2}, {"I love baseball"=>1}]

Answer 2

Yes, you can do it with a named scope inside your model (rails 3+ syntax):

scope :title_count, select( id, title, count(*) AS tcount ).
    where( created_at >= ? , 10.days.ago).
    group( id, title ).
    order( tcount desc )

In your controller:

@posts = Post.title_count

Answer 3

Something like this?

@blog_post_counts = Post.find(
  :all, 
  :select => "COUNT(*) AS count, title", 
  :group  => "title", 
  :order  => "count DESC"
)

当然,你需要修改询问,以便列入你的条件。

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