Skip to main content

what is doctrine hydration?



I've read about hydration in doctrine's documentation but I still can't understand what it is.





Could someone please explain?



Source: Tips4all

Comments

  1. Hydration is a method used to return query results. For example:


    HYDRATE_ARRAY - This will return you an array of records that are represented by another array:

    $q = Doctrine_Query::create()
    ->from('Post p')
    ->setHydrationMode(Doctrine::HYDRATE_ARRAY);


    $resultSet = $q->execute(); // $resultSet is an array


    foreach ($resultSet as $post) {
    // $post is an array
    echo $post['title'];
    }

    HYDRATE_RECORD - This will return you an collection (Doctrine_Collection) of objects:

    $q = Doctrine_Query::create()
    ->from('Post p')
    ->setHydrationMode(Doctrine::HYDRATE_RECORD); // Unnecessary, HYDATE_RECORD is default method


    $resultSet = $q->execute(); // $resultSet is an Doctrine_Collection object


    foreach ($resultSet as $post) {
    // $post is an Post object
    echo $post->getTitle();
    echo $post['title']; // Each Doctrine's Model object implements ArrayAccess interface so this is possible
    echo $post->myCustomMethod();
    }

    HYDRATE_SINGULAR_SCALAR - Will return the value of first column of query's result:

    $q = Doctrine_Query::create()
    ->select('p.created_at')
    ->from('Post p')
    ->where('p.id = ?', 321)
    ->setHydrationMode(Doctrine::HYDRATE_SINGULAR_SCALAR);


    $createdAt = $q->execute(); // $createdAt has value of first column from first record from result set (eg.: 2008-04-06 21:22:35)



    There is a few more methods , you can read about each in documentation.

    ReplyDelete
  2. Doctrine documentation reference explaining HYDRATION:
    http://www.doctrine-project.org/docs/orm/2.0/en/reference/dql-doctrine-query-language.html#query-result-formats

    ReplyDelete
  3. $q->fetchOne(array(), Doctrine_Core::HYDRATE_ARRAY);

    Is just used to return a simple array instead of a doctrine collection object.

    ReplyDelete

Post a Comment

Popular posts from this blog

Slow Android emulator

I have a 2.67 GHz Celeron processor, 1.21 GB of RAM on a x86 Windows XP Professional machine. My understanding is that the Android emulator should start fairly quickly on such a machine, but for me it does not. I have followed all instructions in setting up the IDE, SDKs, JDKs and such and have had some success in staring the emulator quickly but is very particulary. How can I, if possible, fix this problem?