执行的sql语句:SELECT id,nav,title,title_color,posttime,attr,is_bold,is_forward,thumb FROM web_article where nav= and is_online=1 order by sort desc,id desc limit 8
错误提示:SQLSTATE[42000]: Syntax error or access violation: 1064 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 is_online=1 order by sort desc,id desc limit 8' at line 1