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POHelp with a complex ActiveRecord query that has too many joins
 

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  1. POHelp with a complex ActiveRecord query that has too many joins
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    <p>I have the following models</p> <pre><code>class User &lt; ActiveRecord::Base has_many :occupations, :dependent =&gt; :destroy has_many :submitted_jobs, :class_name =&gt; 'Job', :foreign_key =&gt; 'customer_id' has_many :assigned_jobs, :class_name =&gt; 'Job', :foreign_key =&gt; 'employee_id' end class Job &lt; ActiveRecord::Base belongs_to :customer, :class_name =&gt; 'User', :foreign_key =&gt; 'customer_id' belongs_to :employee, :class_name =&gt; 'User', :foreign_key =&gt; 'employee_id' belongs_to :field end class Occupation &lt; ActiveRecord::Base belongs_to :user belongs_to :field belongs_to :expertise end </code></pre> <p>along with <code>Field</code> (just name and id) and <code>Expertise</code> (name and integer rank).</p> <p>I need to create a filter that works like the following pseudocode</p> <pre><code>select * from jobs where employee_id == current_user_id or employee_id == 0 and current_user has occupation where occupation.field == job.field and if job.customer has occupation where occupation.field == job.field current_user.occupations must include an occupation where field == job.field and expertise.rank &gt; job.customer.occupation.expertise.rank </code></pre> <p>You can see how I quickly exhaust my knowledge of SQL with a query this complex.</p> <p>How would you do it? The proper SQL would be great, but if a Rails person can point me towards the correct way to do it with ActiveRecord methods, that's great too. Or maybe I'm not structuring my models very well; I'm open to all kinds of suggestions.</p> <p>Thanks!</p>
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