title: Postgres HStore Errors - Unknown Operator
body: <p>My ruby code:</p>
  
  <pre><code>Portfolio.where("data @&gt; (:key =&gt; :value)",     :key =&gt; 'CSJ', :value =&gt; '0.1')
  </code></pre>
  
  <p>Generates the following SQL:</p>
  
  <pre><code>"SELECT \"portfolios\".* FROM \"portfolios\"  WHERE (data @&gt; ('CSJ' =&gt; '0.1'))"
  </code></pre>
  
  <p>Comes up with this error:</p>
  
  <pre><code>Error: PG::Error: ERROR:  operator does not exist: unknown =&gt; unknown
  LINE 1: ...olios".* FROM "portfolios"  WHERE (data @&gt; ('CSJ' =&gt; '0.1'))
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
  : SELECT "portfolios".* FROM "portfolios"  WHERE (data @&gt; ('CSJ' =&gt; '0.1'))
  </code></pre>
  
  <p>Postgresql 9.1.4, Rails 3.2.7/8, using activerecord-postgres-hstore gem with the following in my model code:</p>
  
  <pre><code>serialize :data, ActiveRecord::Coders::Hstore
  </code></pre>
  
  <p>Help would be appreciated!</p>