一千萬個為什麽

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什麽是學說水合作用?

我已經讀過關於學說文獻中的水合作用,但我仍然無法理解它是什麽。

有人可以解釋一下嗎?

最佳答案

水合是一種用於返回查詢結果的方法。例如:

  1. 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'];
    }
    
  2. 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();
    }
    
  3. 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)
    

還有一些方法,您可以在文檔中閱讀每個方法。

轉載註明原文: 什麽是學說水合作用?