<?php
(...)
        $query = '
            SELECT SQL_CALC_FOUND_ROWS
                k.id,
                k.name,
            FROM
                kantoren AS k
            WHERE
                ' . (! empty($this->vars['name'])   ? 'AND k.name LIKE ?' : '1') . '
            GROUP BY
                k.id
            ORDER BY
                k.name';

        $tokens = array();

        foreach ($this->vars as $key => $var) {
            if (!empty($var)) $tokens[] = $var;
        }

        $this->results = Zend_Registry::get('database')->query($query, $tokens);

/*
If I have this:
$this->vars['name']  = "a%";
... I get a mysql error, because it's missing the quotes around it. (needs to be LIKE "a%", actualy is LIKE a%)

If I have this:
$this->vars['name'] = " 'a%' ";
... I get a mysql error, because the quotation mark gets shashed (LIKE \'a%\')
*/