order by not ordering as expected...

rubyonrails-talk
1

Hi everyone,

I have an app in which I am attempting to add a blog to.

I have the blog and commenting system working. It has 2 tables:

1: blogposts (stores the actual blog topics/stories) 2: blogcomments (stores the comments for each blog created)

so - I've been playing around with the layout, as I think having the most recent posts at the top would be more logical.

Below is the code I have which creates the comment: (and attempts to order the comments accordingly)

def comment      @blogcomment = Blogcomment.find(:all, :order => "created_at desc")

      @user = User.find(session[:user_id])

     Blogpost.find(params[:id]).blogcomments.create(params[:comment])         flash[:notice] = "Added your comment"         redirect_to :action => "show", :id => params[:id]

  end

Any ideas?

Thanks for reading...

2

take a gander at the development.log - find that sql query that is being generated by that find. Try that query on your DBMS and see if it returns the blogposts in the order you expect.

3

Hmm,

for some reason the log isn't showing the order by clause:

Rendering blogposts/show   e[4;35;1mBlogcomment Load (0.4ms)e[0m e[0mSELECT * FROM `blogcomments` WHERE (`blogcomments`.blogpost_id = 17) e[0m   e[4;36;1mBlogcomment Columns (1.3ms)e[0m e[0;1mSHOW FIELDS FROM `blogcomments`e[0m Completed in 133ms (View: 54, DB: 8) | 200 OK [http://localhost/ blogposts/17]

4

it has to - it shows every query

5

what I mean is that the orderby isn't been used.

the latest entry in the log just shows the select query without the order by.

6

that can't be - either your syntax is incorrect and it shows an error in the log and on the screen, or it is correct and it shows the SELECT with the ORDER clause. Your syntax appears to be correct, by the way.

7

Hmm,

for some reason the log isn't showing the order by clause:

Rendering blogposts/show [4;35;1mBlogcomment Load (0.4ms) [0m [0mSELECT * FROM `blogcomments` WHERE (`blogcomments`.blogpost_id = 17) [0m [4;36;1mBlogcomment Columns (1.3ms) [0m [0;1mSHOW FIELDS FROM `blogcomments` [0m Completed in 133ms (View: 54, DB: 8) | 200 OK [http://localhost/ blogposts/17]

You are looking at the wrong query. That is the one for Blogpost.find(params[:id]).... The one you have sorted is @blogcomment = Blogcomment.find(:all, :order => "created_at desc") which should appear above that one. You have not specified a sort in the Blogpost query.

Colin

8

Try this - check that you are not calling the find somewhere else. If necessary, be sure and put a debugger break point and see what code is really executing.

9

ah yes... :slight_smile:

It is in the log:

0mSELECT * FROM `blogcomments` ORDER BY created_at desc LIMIT 1

So if it is in the log, why isn't it ordering the comments?

10

ah yes... :slight_smile:

It is in the log:

0mSELECT * FROM `blogcomments` ORDER BY created_at desc LIMIT 1

So if it is in the log, why isn't it ordering the comments?

What is it that seems to not be sorted? @blogcomment should be sorted but you have done nothing to sort blogposts.comments.

Have you tried breaking in after the find to inspect the data as suggested by another post?

By the way could you avoid top posting please, it is easier to follow the thread if replies are inserted into the previous mail.

Colin

11

RubyonRails_newbie wrote:

def comment      @blogcomment = Blogcomment.find(:all, :order => "created_at desc")

I don't understand the point to this. See next comment...

      @user = User.find(session[:user_id])

Nor this...

     Blogpost.find(params[:id]).blogcomments.create(params[:comment])         flash[:notice] = "Added your comment"         redirect_to :action => "show", :id => params[:id]

Here you are unconditionally redirecting to :action => "show" so what's the point of the above fetch of Blogcomment?

  end

By the way, this method is trying to do too much.

- It's fetching an array of Blogcomments (that it doesn't seem to do anything with) - It finds a user (and doesn't seem to use it either) - It finds a Blogpost and creates a new Blogcomment on it. - It sets flash[:notice] - And finally redirects to the "show" action

The only effective thing it does should be handled by the Blogcomment's "create" method anyway. At least in the modern RESTful Rails world. You have written a custom method for something that can be easily handled by the basic CRUD actions of RESTful controllers.

The redirect_to will create a new request/response cycle causing all instance variables set in this method to be freed for garbage collection.

12

RubyonRails_newbie wrote:

ah yes... :slight_smile:

It is in the log:

0mSELECT * FROM `blogcomments` ORDER BY created_at desc LIMIT 1

So if it is in the log, why isn't it ordering the comments?

'LIMIT 1' at the end of that SQL query means that only one record is being returned. Either you haven't found the right query in the log, or something in the Blogcomment model is preventing more records being returned via a find(:all).