cakephp中使用 find('count')方法

对于find('count',array('group'=>'user_id'));

Model.php中这样描述:

 /**
  * Handles the before/after filter logic for find('count') operations. Only called by Model::find().
  *
  * @param string $state Either "before" or "after"
  * @param array $query
  * @param array $results
  * @return integer The number of records found, or false
  * @see Model::find()
  */
     protected function _findCount($state, $query, $results = array()) {
         if ($state === 'before') {
             if (!empty($query['type']) && isset($this->findMethods[$query['type']]) && $query['type'] !== 'count') {
                 $query['operation'] = 'count';
                 $query = $this->{'_find' . ucfirst($query['type'])}('before', $query);
             }

             $db = $this->getDataSource();
             $query['order'] = false;
             if (!method_exists($db, 'calculate')) {
                 return $query;
             }

             if (!empty($query['fields']) && is_array($query['fields'])) {
                 if (!preg_match('/^count/i', current($query['fields']))) {
                     unset($query['fields']);
                 }
             }

             if (empty($query['fields'])) {
                 $query['fields'] = $db->calculate($this, 'count');
             } elseif (method_exists($db, 'expression') && is_string($query['fields']) && !preg_match('/count/i', $query['fields'])) {
                 $query['fields'] = $db->calculate($this, 'count', array(
                     $db->expression($query['fields']), 'count'
                 ));
             }

             return $query;
         }

         foreach (array(0, $this->alias) as $key) {
             if (isset($results[0][$key]['count'])) {
                 if ($query['group']) {
                     return count($results);
                 }

                 return intval($results[0][$key]['count']);
             }
         }

         return false;
     }

在cakephp测试用例中，有这样的描述：

 $expected = count($Article->find('all', array(
             'fields' => array('Article.user_id'),
             'conditions' => array('Article.user_id' => 1),
             'group' => 'Article.user_id')
         ));
 $result = $Article->find('count', array(
             'conditions' => array('Article.user_id' => 1),
             'group' => array('Article.user_id'),
         ));

$expected 和 $result 的结果是一样的。那么使用count，group统计也是可行的。

使用find('count',array('fields'=>'distinct user_id'));效果也是一样的。