Order of selectors in $pages->find();

[Zeka]

Hi.

I just found out some strange behavior in selectors. There are two snippets of code with small difference in order of selectors. 

First example returns all pages which match "has_parent" selector even if they are not "blog-post" template (not expected result) , but the second one returns only "blog-post" pages ( expected result) . 

$categories = $page->children("template=blog")->add($page);
$items = $pages->find("template=blog-post, has_parent={$categories}, limit=7");

$categories = $page->children("template=blog")->add($page);
$items = $pages->find("has_parent={$categories}, template=blog-post, limit=7");

Is there any documentation on how order of selectors affect the results? 

[kongondo]

FWIW, here are the resultant queries (similar, not identical to yours) for the two finds:

Find 1:

$categories = $page->children("template=blog")->add($page);
$selector = "template=blog-post, has_parent={$categories}, limit=7";
$query = wire('pages')->getPageFinder()->find(new Selectors($selector), array('returnQuery' => true))->getQuery();
echo $query;

Resultant Query:

SELECT SQL_CALC_FOUND_ROWS pages.id,pages.parent_id,pages.templates_id FROM `pages` WHERE (pages.templates_id=77) AND pages.parent_id IN (SELECT pages_id FROM pages_parents WHERE parents_id=3545 OR pages_id=3545) OR pages.parent_id IN (SELECT pages_id FROM pages_parents WHERE parents_id=3560 OR pages_id=3560) OR pages.parent_id IN (SELECT pages_id FROM pages_parents WHERE parents_id=3565 OR pages_id=3565) OR pages.parent_id IN (SELECT pages_id FROM pages_parents WHERE parents_id=1044 OR pages_id=1044) AND (pages.status<1024) GROUP BY pages.id LIMIT 0,7

 

Find 2:

$categories = $page->children("template=blog")->add($page);
$selector = "has_parent={$categories}, template=blog-post, limit=7";
$query = wire('pages')->getPageFinder()->find(new Selectors($selector), array('returnQuery' => true))->getQuery();
echo $query;

Resultant Query:

SELECT SQL_CALC_FOUND_ROWS pages.id,pages.parent_id,pages.templates_id FROM `pages` WHERE pages.parent_id IN (SELECT pages_id FROM pages_parents WHERE parents_id=3545 OR pages_id=3545) OR pages.parent_id IN (SELECT pages_id FROM pages_parents WHERE parents_id=3560 OR pages_id=3560) OR pages.parent_id IN (SELECT pages_id FROM pages_parents WHERE parents_id=3565 OR pages_id=3565) OR pages.parent_id IN (SELECT pages_id FROM pages_parents WHERE parents_id=1044 OR pages_id=1044) AND (pages.templates_id=77) AND (pages.status<1024) GROUP BY pages.id LIMIT 0,7

I am guessing (am no SQL guru) the key thing is that we are dealing with an AND selector, maybe?

Edit: Me thinks this is a bug in the selector engine itself? 

Edited February 2, 2017 by kongondo

[LostKobrakai]

has_parent does not support multiple alternative values with pipes. Only "hackish" version is to use OR groups like so: (has_parent=$cat1), (has_parent=$cat2)

[kongondo]

Actually @LostKobrakai, it does as of ProcessWire 2.5.22? No?

https://processwire.com/blog/posts/processwire-core-and-profields-updates-2.5.22/#has_parent-selectors-now-support-multi-value

Edited February 2, 2017 by kongondo

[LostKobrakai]

I'm not 100% sure about 3.0, but I've a 2.7 installation, where this caused me so much trouble I know for a fact that it doesn't work.

[kongondo]

You are right, Benjamin. If one changes the selector to match only 1 parent like shown below, the two finds become equivalents. 

// these two are equivalents
$items = $pages->find("template=minimal, has_parent={$page}, limit=10");
$items = $pages->find("has_parent={$page}, template=minimal, limit=10");

Do you know if a bug report has been filed about this?

 

Edited February 2, 2017 by kongondo

[LostKobrakai]

Had to search hard, but found it: https://github.com/ryancramerdesign/ProcessWire/issues/1232

Edit: And the new one: https://github.com/processwire/processwire-requests/issues/17

[kongondo]

Excellent! Have upvoted the new one. We will also need to update the Docs. The selectors docs says it doesn't work; the blog post says it does .

[LostKobrakai]

I really feel this should be fixed, especially as the OR group syntax does work.

[kongondo]

Maybe we should file it as a bug...(which it is, since it has been implemented since 2.5.22 but it's not working), rather than a request?

[LostKobrakai]

Yeah, wasn't to confident as it has been around a long time as issue on the old repo

[kongondo]

True, but not sure Ryan is monitoring issues in the old repo .

[LostKobrakai]

Can someone of you guys test out the new commit of Ryan? My project with that issue is currently stuck on 2.7. 

[Zeka]

I just tested it with the new commit and it works as expected.