curator

// Entity1, она же table1
/**
 * @OneToOne(targetEntity="Entity2", mappedBy="parent")
 */
private $child;

// Entity2, она же table2
/**
 * @OneToOne(targetEntity="Entity1", inversedBy="child")
 * @JoinColumn(name="table1_id", referencedColumnName="id")
 */
private $parent;

$getParams = $this->getRequest()->query->all();

$params = array_filter($getParams, function($el) {
    return !empty($el);
});

$queryBuilder = $this->getDoctine()
    ->getRepository('Entity1')
    ->createQueryBuilder('t')
    ->leftJoin('t.child', 'e');

foreach ($params as $key => $val)
{
    $where = sprintf('e.%s = :%s', $key, $key);

    $queryBuilder
        ->andWhere($where)
        ->setParameter($key, $value);
}

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