错误：在非对象上调用成员函数find（）

Question

我是php新手。我有一个简单的错误，但无法解决问题。

  

错误：在非对象上调用成员函数find（）

     

文件：   /var/www/html/cake27/Temploc/Controller/TemperatureReadingsController.php

     

行：59

这是订单中脚本的一部分，并且对58,59,60,61行进行了分类：

public function edit($id = null) {
    if (!$this->TemperatureReading->exists($id)) {
        throw new NotFoundException(__('Invalid temperature reading'));
    }
    if ($this->request->is(array('post', 'put'))) {
        if ($this->TemperatureReading->save($this->request->data)) {
            $this->Session->setFlash(__('The temperature reading has been saved.'));
            return $this->redirect(array('action' => 'index'));
        } else {
            $this->Session->setFlash(__('The temperature reading could not be saved. Please, try again.'));
        }
    } else {
        $options = array('conditions' => array('TemperatureReading.' .$this->TemperatureReading->primaryKey => $id));

$ this-＆gt; request-＆gt; data = $ this-＆gt; TemperatureReading-＆gt; find（＆＃39; first＆＃39;，$ options）;

58- }

59- $locations = $this->TemperatureReading->Location->find('list');

60-
        $this->set(compact('locations'));

61- }