写小程序接口时phpcms中根目录下添加一个接口文件中，添加下面的代码：

define('PHPCMS_PATH',dirname(__FILE__).DIRECTORY_SEPARATOR);

includePHPCMS_PATH.'/phpcms/base.php';

$type = 'index';

$res = array();

switch ($type) {

      case 'index':

       $db = pc_base::load_model('news_model');

       $res['lunbo'] = $db -> select('catid=9','thumb','','id');

       break;

}

测试发现报错，不存在$db，原因是phpcms中没有news_model这个类文件，解决办法在/phpcms/model/下加上news_model.class.php，同时加上代码：

<?php

defined('IN_PHPCMS')or exit('No permission resources.');

pc_base::load_sys_class('model',0);

class news_modelextends model {

      public $table_name = '';

      public function __construct() {

           $this->db_config =pc_base::load_config('database');

           $this->db_setting = 'default';

           $this->table_name = 'news';

           parent::__construct();

      }

}

?>

就可以了。