php - 复杂分页与 NOT IN 条件 cakephp 2

Question

我有一个小问题，无法让我的查询以正确的方式工作。

我的查询应该为我提供实际学期的所有讲座，但仅限于我尚未参加的讲座。所以在 SQL 中它将是:

SELECT * FROM lectures WHERE semester = $currentSemester AND lectures.id NOT IN (SELECT lectures_id FROM participaters WHERE user_id = $this->Auth->user('id'))

我已经得到的是以下内容:

$this->paginate = array(
        'conditions' => array(
            'Lecture.semester >=' => $currentSemester,
            'not' => array(
                'Lecture.id' => array(
                ),
            ),
        ),
        'order' => array(
            'Lecture.name' => 'asc',
        ),
        'contain' => array(
            'Participater',
        ),
    );
    $this->set('lectures', $this->paginate($this->Lecture));

如何使用 user_id 定义条件？也许你们中有人可以帮忙？如果有任何错误，我的英语很抱歉:)

Answer 1

首先找到要在查询中排除的 ID 列表，然后使用此 ID 列表以及“Lecture.id !=” => $ids 等条件。

假设您有模型参与者链接到模型讲座，查询可能如下所示。

//retrieve the list of excluded ids
$excluded_ids = $this->Lecture->Participater->find('list',array(
    'conditions' => array(
        'Participater.user_id' => $this->Auth->user('id')
    ),
    'fields' => array('lecture_id')
);

$this->paginate = array(
    'conditions' => array(
        'Lecture.semester >=' => $currentSemester,
        'Lecture.id !=' => $excluded_ids,//put the excluded ids here
    ),
    'order' => array(
        'Lecture.name' => 'asc',
    ),
    'contain' => array(
        'Participater',
    ),
);
$this->set('lectures', $this->paginate($this->Lecture));