涉及doQuery（）的函数不起作用

Currently, I have a class

class view {

    var $db;
    var $sql = "";
    var $sql_params = array();
    var $resultList;

And inside this class, there is a 'function get_list($option)'

    //$db = new db();
        //$db->getConnection();
        $rs = $this->db->doQuery($this->sql, $this->sql_params);
        $this->resultList = $rs;

        if($option == 'html_table') {
            if(!count($rs)) {
                $out = "<center>No Results, please search again.</center>";
            } else {
                if(isset($_SESSION['magickey'])) {
                    $loggedIn = true;
                } else {
                    $loggedIn = false;
                }

I know the reason it's returning error is because there's something wrong with

this one line

$rs = $this->db->doQuery($this->sql, $this->sql_params);

the function get_list take up parameter

get_list('html_table');

So what's wrong with that line? This is the error message:

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42S22]: 
Column not found: 1054 Unknown column 'q1.country' in 'where clause'' in /usr/local/zend/share/ZendFramework/library/Zend/Db/Statement/Pdo.php on line 234 ( ! )
PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'q1.country' in 'where clause' in /usr/local/zend/share/ZendFramework/library/Zend/Db/Statement/Pdo.php on line 228