[#MDEV-22064] result_metadata()->fetch_fields() returns incorrect orgname and orgtable for select statements with subquery in FROM clause

The statement metadata does not correctly identify the underlying table and column. This is a regression vs e.g. MySQL 5.1.73.

This behavior has been reproduced in several server environments and also with the mariadb client for nodejs.

Impact: Cannot determine application-level metadata and security attributes for the tables and columns queried.

<?php

/*

 * connect parameters

*/

$host = 'localhost';

$id = 'holson';

$pwd = 'xxxxxxxx';

$dbname = 'alias';

/*

 * connect

*/

$link = @mysqli_connect($host, $id, $pwd);

if ($link === false) {

    echo 'unable to connect to database - incorrect connect parametsrs?' . PHP_EOL;

    exit(1);

mysqli_select_db($link, $dbname);

/*

 * prepare database

*/

$ddl = "drop table if exists Site";

$r = mysqli_query($link, $ddl);

$ddl = "create table Site (Name varchar(50))";

$r = mysqli_query($link, $ddl);

/*

 * execute test case

*/

$sql="

    select

        SiteName

    from (select Name as SiteName from Site) as s

";

echo 'DDL: ' . $ddl . PHP_EOL;

echo 'SQL: ' . $sql . PHP_EOL;

echo 'Expect: orgname => Name, orgtable => Site'. PHP_EOL;

$stmt = mysqli_prepare($link, $sql);

$fields = $stmt->result_metadata()->fetch_fields();

echo 'Result ( $stmt->result_metadata()->fetch_fields() ): ';

print_r($fields);

?>

[MDEV-22064] result_metadata()->fetch_fields() returns incorrect orgname and orgtable for select statements with subquery in FROM clause Created: 2020-03-27 Updated: 2020-05-04 Resolved: 2020-05-04
Status:	Closed
Project:	MariaDB Server
Component/s:	Server
Affects Version/s:	5.5.64, 10.3.22
Fix Version/s:	N/A