Search logic

If I have this table…

id
created_at
updated_at
user_id
value

…and you can add several posts per user, how do I find all latest
posts for each user?

I think I’m on the right track. But I get the first post for each user,
not the latest. This is what I use.

Model.all(:select => “*, max(id)”, :group => :user_id)

How do get the latest?

On Mon, Feb 21, 2011 at 2:48 PM, Paul B.
[email protected]wrote:

I think I’m on the right track. But I get the first post for each user,
not the latest. This is what I use.

Model.all(:select => “*, max(id)”, :group => :user_id)

How do get the latest?

In Rails 3 syntax,
Post.where(:user_id => given_user_id).group(:user_id).order(:updated_at
DESC).limit(number).group_by(:&user_id)
First, group the results by user_id.
Then, order the updated_at or created_at in DESC order.
Then, you can limit the results for each user by passing a number.
Then, finally return a hash of all the results with keys as user_id for
easier and better retrieval.

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