Join subquery with doctrine 2 DBAL

Question

I\'m refactoring a Zend Framework 2 application to use doctrine 2.5 DBAL instead of Zend_DB (ZF1). I have the following Zend_Db query:

$subS         


        

Answer 1

I've found a solution by adapting this DQL example to DBAL. The trick is to get the raw SQL of the subquery, wrap it in brackets, and join it. Parameters used in the subquery must be set in the main query:

$subSelect = $connection->createQueryBuilder()
    ->select(array('userSurveyID', 'MIN(timestamp) timestamp'))
    ->from('user_survey_status_entries')
    // Instead of setting the parameter in the main query below, it could be quoted here:
    // ->where('status = ' . $connection->quote(UserSurveyStatus::ACCESSED))
    ->where('status = :status')
    ->groupBy('userSurveyID');

$select = $connection->createQueryBuilder()
    ->select($selectColNames)
    ->from('user_surveys', 'us')
    // Get raw subquery SQL and wrap in brackets.
    ->leftJoin('us', sprintf('(%s)', $subSelect->getSQL()), 'firstAccess', 'us.userSurveyID = firstAccess.userSurveyID')
    // Parameter used in subquery must be set in main query.
    ->setParameter('status', UserSurveyStatus::ACCESSED)
    ->where('us.surveyID = :surveyID')->setParameter('surveyID', $surveyID);

Answer 2

To answer this part of your question:

I can't figure out how to join the subquery using the doctrine 2.5 query builder

You can make 2 query builder instances and use the DQL from the second one inside a clause of your first query. An example:

->where($qb->expr()->notIn('u.id', $qb2->getDQL())

Check examples here or here or find more using Google

Answer 3

Selected answer is over-complicated and the second one is wrong (it won't return anything is the condition is totally fullfilled, meaning if there is no row at all returned by the sub-query).

But yes, you can refactor to use IN:

$qb->leftJoin('user_survey_status_entries', 
              'firstAccess',
              Join::WITH, 
              $qb->expr()->in($qb2->getDQL())
);

In your case, don't forget to move the us.userSurveyID = firstAccess.userSurveyID condition into $qb2.