什么是学说水合作用？

Question

我已经读过关于学说文献中的水合作用,但我仍然无法理解它是什么.

有人可以解释一下吗？

Answer 1

水合是一种用于返回查询结果的方法.例如:

1. HYDRATE_ARRAY - 这将返回一个由另一个数组表示的记录数组:

   $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- 这将返回一个对象的集合(Doctrine_Collection):

   $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 - 将返回查询结果第一列的值:

    $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)
   

还有一些方法,您可以在文档中阅读每个方法.