_query example

class Zend_Validate_Db_RecordExists extends Zend_Validate_Db_Abstract
{
    public function isValid($value)
    {
        $valid = true;
        $this->_setValue($value);

        $result = $this->_query($value);
        if (!$result) {
            $valid = false;
            $this->_error(self::ERROR_NO_RECORD_FOUND);
        }

        return $valid;
    }
}

    public function load($id, $doNotTestCacheValidity = false)
    {
        $this->_checkAndBuildStructure();
        $sql = "SELECT content FROM cache WHERE id='$id'";
        if (!$doNotTestCacheValidity) {
            $sql = $sql . " AND (expire=0 OR expire>" . time() . ')';
        }
        $result = $this->_query($sql);
        $row = @sqlite_fetch_array($result);
        if ($row) {
            return $row['content'];
        }
        return false;
    }

    /** * Test if a cache is available or not (for the given id) * * @param string $id Cache id * @return mixed|false (a cache is not available) or "last modified" timestamp (int) of the available cache record */

class Zend_Validate_Db_NoRecordExists extends Zend_Validate_Db_Abstract
{
    public function isValid($value)
    {
        $valid = true;
        $this->_setValue($value);

        $result = $this->_query($value);
        if ($result) {
            $valid = false;
            $this->_error(self::ERROR_RECORD_FOUND);
        }

        return $valid;
    }
}