出错信息：Database SQL: "SELECT A.*,B.content,C.name as class_name,C.app,C.urlname as class_urlname,C.image as class_image FROM dux_content as A inner join dux_content_article as B ON A.content_id = B.content_id inner join dux_category as C ON A.class_id = C.class_id WHERE `A`.`status` = '1' AND A.time < AND `C`.`class_id` = '' ORDER BY A.time DESC,A.content_id DESC LIMIT 1". ErrorInfo: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AND `C`.`class_id` = '' ORDER BY A.time DESC,A.content_id DESC LIMIT 1' at line 1

出错文件：/usr/home/qxu1587720455/htdocs/framework/base/db/MysqlDriver.php

错误行：39

Trace信息：
#0 /usr/home/qxu1587720455/htdocs/framework/base/db/MysqlDriver.php(20) framework\base\db\MysqlDriver->query()
#1 /usr/home/qxu1587720455/htdocs/framework/base/Model.php(76) framework\base\db\MysqlDriver->select()
#2 /usr/home/qxu1587720455/htdocs/framework/base/Model.php(49) framework\base\Model->select()
#3 /usr/home/qxu1587720455/htdocs/app/article/model/ContentArticleModel.php(108) framework\base\Model->find()
#4 /usr/home/qxu1587720455/htdocs/app/article/controller/ContentController.php(76) app\article\model\ContentArticleModel->getWhereInfo()
#5 /usr/home/qxu1587720455/htdocs/framework/base/App.php(47) app\article\controller\ContentController->index()
#6 /usr/home/qxu1587720455/htdocs/framework/core.php(97) framework\base\App::run()
#7 /usr/home/qxu1587720455/htdocs/index.php(15) require()