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Paginate Through A Randomized List Of Blog Posts Using Will_paginate

- 1 answer

I want to give users the ability to page through my blog posts in random order.

I can't implement it like this:

@posts = Post.paginate :page => params[:page], :order => 'RANDOM()'

since the :order parameter is called with every query, and therefore I risk repeating blog posts.

What's the best way to do this?

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Answer

RAND accepts a seed in MySQL:

RAND(N) 

From the MySQL docs:

RAND(), RAND(N)

Returns a random floating-point value v in the range 0 <= v < 1.0. If a constant integer argument N is specified, it is used as the seed value, which produces a repeatable sequence of column values. In the following example, note that the sequences of values produced by RAND(3) is the same both places where it occurs.

Other databases should have similar functionality.

If you use the SAME seed each time you call RAND, the order will be consistent across requests and you can paginate accordingly.

You can then store the seed in the user's session - so each user will see a set of results unique to them.

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source: stackoverflow.com
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