Re: Following links in QB

Hi,

Piotras wrote:
> 1. How it affects ML objects?

No changes.

> 2. What about limit or group?

Limit works just as it does now. The limits set on the subordinate query 
builders will just be ignored, but the main query builder limits work 
just as before.

group?

> 3. How select will look like in such cases?

Simplified version (no ML, sitegroups, etc.):

     $qb = new MidgardQueryBuilder("midgard_article");
     $subqb = $qb->forward_join("author");
     $subqb->add_constraint("username", "=", "foo");
     $qb->execute();
     => SELECT a.* FROM article AS a, person AS b
        WHERE a.author = b.id AND b.username='foo'

     $qb = new MidgardQueryBuilder("midgard_person");
     $subqb = $qb->backward_join("midgard_member", "uid");
     $subqb->add_constraint("gid", "=", 123);
     $qb->execute();
     => SELECT a.* FROM person AS a
        WHERE (SELECT COUNT(*) FROM member AS b
               WHERE b.uid=a.id AND b.gid=123) > 0;
        (could also be implemented as a standard join)

     $qb = new MidgardQueryBuilder("midgard_person");
     $subqb = $qb->backward_join("midgard_member", "uid");
     $subsubqb => $subqb->forward_join("gid");
     $subsubqb->add_constraint("name", "LIKE", "% Corp.");
     $qb->execute();
     => SELECT a.* FROM person AS a
        WHERE (SELECT COUNT(*) FROM member AS b, grp AS c
               WHERE b.uid=a.id AND b.gid=c.id
               AND c.name LIKE '% Corp.') > 0;
        (could also be implemented as a standard join)

These are just general examples, the actual details are of course more 
complex.

BR,

Jukka Zitting