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。