:order_by => ["RAND()"]

Rails
1

Hi there,

I’m trying to grab a random row out of a database and I keep getting the
error:

Couldn’t find Reason with ID=random

Here’s my controller:

@reason = Reason.find(:first, :order => [“RAND()”])

I think that’s right, right? I know that RAND() is an expensive
operation, but it’s a small table so I’m not too worried.

Thanks!

2

Reason.find(Reason.find(:all, :select => :id).map(&:id).rand)

Enjoy.

On Wed, Mar 12, 2008 at 12:20 PM, Dave A. <
[email protected]> wrote:

@reason = Reason.find(:first, :order => [“RAND()”])

I think that’s right, right? I know that RAND() is an expensive
operation, but it’s a small table so I’m not too worried.

Thanks!

Posted via http://www.ruby-forum.com/.

–
Ryan B.

Feel free to add me to MSN and/or GTalk as this email.

3

On 11-Mar-08, at 9:54 PM, Ryan B. (Radar) wrote:

the
error:

Couldn’t find Reason with ID=random

Here’s my controller:

@reason = Reason.find(:first, :order => [“RAND()”])

I think that’s right, right? I know that RAND() is an expensive
operation, but it’s a small table so I’m not too worried.

or…

@reason = Reason.find(:all, :order => “RAND()”, :limit => 1)

(you might need to do a .first on the result set)
Jodi

4

Hmm… I tried what you have to a T (including the .first) and no luck.
Weird! I’ll keep trying stuff.

Jodi S. wrote:

On 11-Mar-08, at 9:54 PM, Ryan B. (Radar) wrote:

the
error:

Couldn’t find Reason with ID=random

Here’s my controller:

@reason = Reason.find(:first, :order => [“RAND()”])

I think that’s right, right? I know that RAND() is an expensive
operation, but it’s a small table so I’m not too worried.

or…

@reason = Reason.find(:all, :order => “RAND()”, :limit => 1)

(you might need to do a .first on the result set)
Jodi

5

Thanks for the patience. I figured it out, and it was an unrelated
routing error. Grr. :slight_smile:

Jodi S. wrote:

On 11-Mar-08, at 10:08 PM, Dave A. wrote:

Hey Dave -

error:

or…

@reason = Reason.find(:all, :order => “RAND()”, :limit => 1)

(you might need to do a .first on the result set)
Jodi

I’m doing that with rails 1.2.3 and mysql 5 (with a few :conditions
and :includes thrown in as well).

Jodi

6

On 11-Mar-08, at 10:08 PM, Dave A. wrote:

Hey Dave -

error:

or…

@reason = Reason.find(:all, :order => “RAND()”, :limit => 1)

(you might need to do a .first on the result set)
Jodi

I’m doing that with rails 1.2.3 and mysql 5 (with a few :conditions
and :includes thrown in as well).

Jodi

7

You could also try using the find_random plugin:
http://www.railslodge.com/plugins/964-find-random

I have not tried using it yet, but it looks well-executed. Has anyone
tried using the find_random plugin with has_finder?

Jason Arora

On Mar 11, 8:33 pm, Dave A. [email protected]