code: public function findPost($search)
      {
          // select
          $qb = $this->getQueryBuilder()
              ->select('p, pTrans')
              ->join('p.translations', 'pTrans')
              ;    
          
          
          // search
          if (!empty($search)) {
              $qb->where('pTrans.title LIKE :search')
                  ->orWhere('pTrans.description LIKE :search')
                  ->setParameter('search', '%'.$search.'%');
          }
  
          $qb->orderBy('p.published', 'DESC');
  
          return $qb->getQuery()->getResult();
      }
docs: Find all rows filtered for DataTables
  
  @param string $search        The search string
  @param int    $sortColumn    The column to sort by
  @param string $sortDirection The direction to sort the column
  
  @return \Doctrine\ORM\Query