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copied!<p>As far as I know, scopes cannot be applied to included associations like this. However, you can specify conditions that should only be applied to the eager loading queries. So with a bit of refactoring, you could have a method that only created the conditions you currently define in your scope:</p> <pre><code>def self.filter_by(options) condition = options[:user_id].nil? ? "true" : "entries.user_id = #{options[:user_id]}" condition += options[:from_date].nil? ? "" : " AND entries.entry_date >= '#{options[:from_date]}'" condition += options[:to_date].nil? ? "" : " AND entries.entry_date <= '#{options[:to_date]}' condition end </code></pre> <p>or a bit more rubyesque:</p> <pre><code>def self.filter_by(options) conditions = [] conditions << "entries.user_id = #{options[:user_id]}" unless options[:user_id].nil? conditions << "entries.entry_date >= '#{options[:from_date]}'" unless options[:from_date].nil? conditions << "entries.entry_date <= '#{options[:to_date]}'" unless options[:to_date].nil? conditions.join(" AND ") end </code></pre> <p>and then chain that method to your eager loading:</p> <pre><code>@projects = current_user.projects.includes(:entries, :to_dos =>[:entries, :tasks => :entries].where(Entry.filter_by(options)) </code></pre> <p>and also reuse it in your scope if you need it independently:</p> <pre><code>scope :filtered_list, lambda { |options| where(Entry.filter_by(options)) } </code></pre> <p>Disclaimer: None of this is tested with your actual model definitions, but it works fine with some pretty equivalent ones that I had lying around.</p> <p>Also note that if the filter options ultimately come from the client side, your condition is vulnerable to SQL injection.</p> <p>Behind the scenes, Rails uses a JOIN to load the relevant data, so that is something to be aware of. It might be a good thing (a few less queries) or a bad thing (if your indexing is suboptimal). That's probably why the <a href="http://guides.rubyonrails.org/active_record_querying.html" rel="nofollow">guide</a> has this to say:</p> <blockquote> <p>Even though Active Record lets you specify conditions on the eager loaded associations just like joins, the recommended way is to use joins instead.</p> </blockquote>

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