/**
* Return the correct character used to quote identifiers (table
* names, column names etc) by looking at the driver being used by PDO.
*/
protected static function _detect_identifier_quote_character() {
    switch(self::$_db->getAttribute(PDO::ATTR_DRIVER_NAME)) {
        case 'pgsql':
        case 'sqlsrv':
        case 'dblib':
        case 'mssql':
        case 'sybase':

        //
        //
        case 'firebird':
        return '"';
        //
        //

        case 'mysql':
        case 'sqlite':
        case 'sqlite2':
        default:
        return '`';
    }
}


/**
* Return the correct word LIMIT wordused 
* by looking at the driver being used by PDO.
*/
protected static function _detect_identifier_limit_word() {
    switch(self::$_db->getAttribute(PDO::ATTR_DRIVER_NAME)) {                

        //
        //
        case 'firebird':
        return 'FIRST ';
        //
        //

        default:
        return 'LIMIT ';
    }
}

/**
* Return the correct word OFFSET wordused 
* by looking at the driver being used by PDO.
*/
protected static function _detect_identifier_offset_word() {
    switch(self::$_db->getAttribute(PDO::ATTR_DRIVER_NAME)) {                

        //
        //
        case 'firebird':
        return 'SKIP ';
        //
        //

        default:
        return 'OFFSET ';
    }
}


/**
* Tell the ORM that you wish to execute a COUNT query.
* Will return an integer representing the number of
* rows returned.
*/
public function count() {
    //$this->select_expr('COUNT(*)', 'count');

    //
    //
    // 'count ' is reseved word in Firebird
    $_order_by = $this->_order_by;
    $this->_order_by = array(); // MP empty order by...
    $this->select_expr('COUNT(*)', 'cnt');

    $result = $this->find_one();
    $this->_order_by = $_order_by;
    return ($result !== false && isset($result->CNT)) ? (int) $result->CNT : 0;
    //
    //

}

/**
* Build a SELECT statement based on the clauses that have
* been passed to this instance by chaining method calls.
*/
protected function _build_select() {
    // If the query is raw, just set the $this->_values to be
    // the raw query parameters and return the raw query
    if ($this->_is_raw_query) {
        $this->_values = $this->_raw_parameters;
        return $this->_raw_query;
    }

    // Build and return the full SELECT statement by concatenating
    // the results of calling each separate builder method.
    return $this->_join_if_not_empty(" ", array(
    $this->_build_select_start(),
    $this->_build_join(),
    $this->_build_where(),
    $this->_build_group_by(),
    $this->_build_order_by(),

    //
    //
(self::$_db->getAttribute(PDO::ATTR_DRIVER_NAME)=='firebird')?'':$this->_build_limit(),
    (self::$_db->getAttribute(PDO::ATTR_DRIVER_NAME)=='firebird')?'':$this->_build_offset(),
    ));
    //
    //

}

/**
* Build the start of the SELECT statement
*/
protected function _build_select_start() {
    $result_columns = join(', ', $this->_result_columns);

    if ($this->_distinct) {
        $result_columns = 'DISTINCT ' . $result_columns;
    }

    //
    //
    if(self::$_db->getAttribute(PDO::ATTR_DRIVER_NAME)=='firebird') {
        $limit = $this->_build_limit(); 
        $offset = $this->_build_offset();               
    }
    else {
        $limit = '';
        $offset = ''; 
    }

    $fragment = "SELECT {$limit} {$offset} {$result_columns} FROM " . $this->_quote_identifier($this->_table_name);

    if (!is_null($this->_table_alias)) {
        $fragment .= " " . $this->_quote_identifier($this->_table_alias);
        }       

    return $fragment;
    //
    //

}