Analyze Explain at mariadb.org doesn't have a redirect link

[liviuconcioiu]

Describe the bug

Analyze Explain at mariadb.org doesn't work as expected.

For simple queries like EXPLAIN SELECT actor_id FROM sakila.actor works.

For complex queries like EXPLAIN SELECT actor_id AS actor_id, (SELECT first_name FROM sakila.actor WHERE actor_id = actor_id ORDER BY actor_id DESC LIMIT 1) AS first_name FROM sakila.actor GROUP BY actor_id it doesn't work. The supposed redirect link is empty.

To Reproduce

Steps to reproduce the behavior:

1. Go to https://demo.phpmyadmin.net/QA_5_1/index.php?route=/sql&db=sakila&table=actor
2. Execute this query EXPLAIN SELECT actor_id AS actor_id, (SELECT first_name FROM sakila.actor WHERE actor_id = actor_id ORDER BY actor_id DESC LIMIT 1) AS first_name FROM sakila.actor GROUP BY actor_id
3. Hover the mouse or click on Analyze Explain at mariadb.org
4. See error

Expected behavior

It should be redirected to mariadb.org with the query.

Screenshots

Client configuration

• Browser: Firefox
• Operating system: Windows

[williamdes]

Thank you!
I was trying to reproduce it after seeing it in production and I could not

Bug confirmed, seems like the url is wrong for some reason

[iifawzi]

Thank you!
I was trying to reproduce it after seeing it in production and I could not

Bug confirmed, seems like the url is wrong for some reason

I'm trying to fix this, but I'm not able to reproduce it, is it sometime work and sometime not? @williamdes
I've tested with the same steps mentioned above, it works.

the exception is that i'm using mac, but It doesn't matter I think.

[liviuconcioiu]

I'm trying to fix this, but I'm not able to reproduce it, is it sometime work and sometime not?

Hi @iifawzi , you can't reproduce it, because you've selected the MariaDB. You have &server=1 in url. This can be reproduced on MySQL only.

[iifawzi]

I've found that the cause of the error is this check

phpmyadmin/libraries/classes/Html/Generator.php

Lines 1154 to 1155 in a0410aa

	if (
	($urlLength > $GLOBALS['cfg']['LinkLengthLimit'])

The maximum is set to 1000:

phpmyadmin/libraries/config.default.php

Lines 2825 to 2833 in a0410aa

	/**
	* Limit for length of URL in links. When length would be above this limit, it
	* is replaced by form with button.
	* This is required as some web servers (IIS) have problems with long URLs.
	* The recommended limit is 2000
	* (see https://www.boutell.com/newfaq/misc/urllength.html) but we put
	* 1000 to accommodate Suhosin, see bug #3358750.
	*/
	$cfg['LinkLengthLimit'] = 1000;

I've tested with 2000 and it worked, but I couldn't find any details about the mentioned bug to take a look. @williamdes

[williamdes]

Thank you all for your comments and work !
I will try to search once more to fix this issue

[williamdes]

I could confirm the bug by changing

EXPLAIN SELECT actor_id AS actor_id, (SELECT first_name FROM sakila.actor WHERE actor_id = actor_id ORDER BY actor_id DESC LIMIT 1) AS first_name FROM sakila.actor GROUP BY actor_id;

into

EXPLAIN SELECT actor_id AS actor_id, (SELECT first_name FROM sakila.actor WHERE actor_id = actor_id ORDER BY actor_id DESC LIMIT 1) AS first_name, (SELECT first_name FROM sakila.actor WHERE actor_id = actor_id ORDER BY actor_id DESC LIMIT 1) AS first_name2 FROM sakila.actor GROUP BY actor_id;

(just adding more length)

[williamdes]

We could probably use https://mariadb.com/kb/en/explain-analyzer-api/
Edit: it seems to just redirect to the website