Symfony3 queryBuilder如何使用OR进行搜索以及如何搜索子字符串？

$queryBuilder = $entityManager->createQueryBuilder();
$queryBuilder->select('p')
    ->from('AppBundle:Product', 'p')
    ->where($queryBuilder->expr()->orX(
        $queryBuilder->expr()->eq('p.name', ':searchTerm'),
        $queryBuilder->expr()->eq('p.description', ':searchTerm')
    ))
    ->setParameter('searchTerm', 'search term');

$results = $queryBuilder->getQuery()->getResult();

$queryBuilder = $entityManager->createQueryBuilder();
$queryBuilder->select('p')
    ->from('AppBundle:Product', 'p')
    ->where($queryBuilder->expr()->like('p.name', ':searchTerm'))
    ->setParameter('searchTerm', '%search%');

$results = $queryBuilder->getQuery()->getResult();