title: In JPA QL,How can I select all country by item's category?
body: <p>Model</p>
  
  <pre><code>Item(id,name,countries,category)
  Category(id,name)
  Country(id,name)
  </code></pre>
  
  <p>Some thing like this (incorrect)</p>
  
  <pre><code>select distinct c 
  from Country c left join Weapon w on c in(w.countries) 
  where w.weaponCategory = :category
  </code></pre>
  
  <p>I don't want to do this in code,fetch by category and iterate,but how to write this JPA QL?</p>