Zend Framework中的Zend_Db不支持模糊查询?解决思路

class Dtstockgrade extends Zend_Db_Table_Abstract {
    
    protected $_name = 'dtstockgrade';
    protected $_db;
    
    public function init(){
        
        $this->_db=$this->getAdapter();    
    }
        public function getListSize($classid='',$author='',$stockcode='',$title='',$time=''){
        if(strlen($classid)>1){
            $where=" classid='".$classid."'";
        }else{
            $where=" createtime > '".$time."'";
            if(strlen($author)>1){
                $where.=" and author like '%".$author."%' ";
            }
            if(strlen($stockcode)>1){
                $where.=" and stockcode='".$stockcode."' ";
            }
            if(strlen($title)>1){
                $where.=" and title like '%".$title."%' ";
            }
        }
        $sql="select count(*) as total from  dtstockgrade where $where";
        //file_put_contents("d://a.txt",$sql); 
        $sql=$this->_db->quoteInto($sql,'');
        $result=$this->_db->query($sql);
        $result=$result->fetchAll();
        return $result;
    }
}