Symfony2 Doctrine query

问题

I'm new in symfony2 , I don't know how to write a below query in symfony2 using createQuery()

select * from Post inner join Category on Post.category_id=Category.id inner join Priority on Post.priority_id=Priority.id order by priority_number desc

I used repository class,in which ,wrote a function

public function findAllOrderedByPriorityPost()
    {

        return $this->getEntityManager()
                ->createQuery('select p,c,pr from RodasysfourmBundle:Post p inner join 
RodasysfourmBundle:Category c  inner join RodasysfourmBundle:Priority pr order by pr.priorityNumber desc')
                ->getResult();
    }

when I used this function,I got the below error

[Semantical Error] line 0, col 85 near 'c inner join': Error: Identification Variable RodasysfourmBundle:Category used in join path expression but was not defined before. 

Also which method is best using this query in a custom repository or as a service?

any help appreciated.

回答1:

DQL in doctrine2 won't know how to join tables if you specify the name of a referenced entity. You can only work with one entity and its fields (which may have relations).

select p,c,pr from RodasysfourmBundle:Post p inner join 
p.Category c inner join c.Priority pr order by pr.priorityNumber desc

来源：https://stackoverflow.com/questions/8265393/symfony2-doctrine-query