Zend_Db_Adapter_Exception example

return;
        }

        // get the dsn first, because some adapters alter the $_pdoType         $dsn = $this->_dsn();

        // check for PDO extension         if (!extension_loaded('pdo')) {
            /** * @see Zend_Db_Adapter_Exception */
            throw new Zend_Db_Adapter_Exception('The PDO extension is required for this adapter but the extension is not loaded');
        }

        // check the PDO driver is available         if (!in_array($this->_pdoType, PDO::getAvailableDrivers())) {
            /** * @see Zend_Db_Adapter_Exception */
            throw new Zend_Db_Adapter_Exception('The ' . $this->_pdoType . ' driver is not currently installed');
        }

        // create PDO connection

        if (!is_array($config)) {
            /* * Convert Zend_Config argument to a plain array. */
            if ($config instanceof Zend_Config) {
                $config = $config->toArray();
            } else {
                /* * @see Zend_Db_Adapter_Exception */
                throw new Zend_Db_Adapter_Exception('Adapter parameters must be in an array or a Zend_Config object');
            }
        }

        $this->_checkRequiredOptions($config);

        $options = [
            Zend_Db::CASE_FOLDING => $this->_caseFolding,
            Zend_Db::AUTO_QUOTE_IDENTIFIERS => $this->_autoQuoteIdentifiers,
            Zend_Db::FETCH_MODE => $this->_fetchMode,
        ];
        $driverOptions = [];

        

     public function limit($sql, $count, $offset = 0)
     {
        $count = intval($count);
        if ($count <= 0) {
            /** @see Zend_Db_Adapter_Exception */
            throw new Zend_Db_Adapter_Exception("LIMIT argument count=$count is not valid");
        }

        $offset = intval($offset);
        if ($offset < 0) {
            /** @see Zend_Db_Adapter_Exception */
            throw new Zend_Db_Adapter_Exception("LIMIT argument offset=$offset is not valid");
        }

        $sql .= " LIMIT $count";
        if ($offset > 0) {
            $sql .= " OFFSET $offset";
        }

    protected function _checkRequiredOptions(array $config)
    {
        // we need at least a dbname         if (! array_key_exists('dbname', $config)) {
            /** @see Zend_Db_Adapter_Exception */
            throw new Zend_Db_Adapter_Exception("Configuration array must have a key for 'dbname' that names the database instance");
        }
    }

    /** * DSN builder */
    protected function _dsn()
    {
        return $this->_pdoType .':'. $this->_config['dbname'];
    }