分组包含模型 [英] grouping contained models

问题描述

PresentationView hasMany SlideView

SlideView 模型具有字段持续时间。

SlideView model has field duration.

presentation_duration = SlideView.duration

The presentation_duration = sum of all SlideView.duration fields from slide views that belong to the presentation.

我想为每个演示文稿使用presentation_duration获取演示文稿的列表（分页）。
到目前为止，我尝试这样：

I want to get list (paged) of presentations with presentation_duration for each presentation. So far I am trying like this:

$this->paginate['contain'] = array(
            'PresentationView' => array(
                'SlideView' => array(
                    'group' => 'SlideView.presentation_view_id',
                                    // 'conditions' => array('group' => 'SlideView.presentation_view_id'),
                )
            )
        ); 

注释行是我尝试的一个选项。

The commented line is an option that I tried.

这两种方法都会出现一些SQL错误：

Both methods end up with some SQL errors:

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'SlideView.group' in 'fieldlist'

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'group' in 'where clause'

似乎包含甚至不识别组键 - 是否甚至可以使用这样的分组？

It seems that contain doesn not even recognize group key - is it even possible to use grouping like this? If yes how I can do it?

推荐答案

不能将'group'传递给'contain'。要执行您希望执行的操作，您需要使用JOIN - 请参阅 CakePHP加入表。

You cannot pass 'group' to your 'contain'. To do what you're hoping to do, you'll need to use JOINs - see CakePHP Joining Tables.

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