[TYPO3-mvc] FYI: Implemented another handy query feature

[Jochen Rau]

Hi.

Wit r1998 of Extbase I have implemented another feature. It is now 
possible to write a property path as first operand of a comparison. For 
example: Inside the PostRepository you can write

public function findTaggedWith($name) {
	$query = $this->createQuery();
	$query->matching($query->equals('tags.name', $name));
	return $query->execute();
}

This will return all Posts that are tagged with the given name. Extbase 
expands this to a INNER JOIN with the Tag table.

This works for 1:1, 1:n, and m:n relations. And even for comma separated 
values. And it works for all comparisons (equals, in, contains, like ...).

And you can go deep into the object graph. Inside the BlogRepository you 
can write:

public function findBlogsWithPostsTaggedWith($name) {
	$query = $this->createQuery();
	$query->matching($query->equals('posts.tags.name', $name));
	return $query->execute();
}

to retrieve all Blogs that have at least one Post tagged with the given 
name. Extbase will expand this recursively to three INNER JOINS (because 
of the  relation table post-tag). I am happy that I don't have to write 
this statement on my own anymore ;-):

SELECT DISTINCT tx_blogexample_domain_model_blog.* FROM 
tx_blogexample_domain_model_blog INNER JOIN 
tx_blogexample_domain_model_post ON 
tx_blogexample_domain_model_blog.uid=tx_blogexample_domain_model_post.blog 
INNER JOIN tx_blogexample_post_tag_mm ON 
tx_blogexample_domain_model_post.uid=tx_blogexample_post_tag_mm.uid_local INNER 
JOIN tx_blogexample_domain_model_tag ON 
tx_blogexample_post_tag_mm.uid_foreign=tx_blogexample_domain_model_tag.uid 
WHERE tx_blogexample_domain_model_tag.name = 'Tag' AND 
tx_blogexample_domain_model_post.deleted=0 AND 
tx_blogexample_domain_model_post.t3ver_state<=0 AND 
tx_blogexample_domain_model_post.hidden=0 AND 
tx_blogexample_domain_model_post.sys_language_uid IN (0,-1) AND 
tx_blogexample_domain_model_post.pid IN (105) AND 
tx_blogexample_domain_model_tag.deleted=0 AND 
tx_blogexample_domain_model_tag.hidden=0 AND 
tx_blogexample_domain_model_tag.pid IN (105)

This feature is still non-api but after a discussion with Karsten I am 
sure he will implement it, too ;-).

Please test it and report regressions (if any ;-))

Regards
Jochen