You should see it: http://www.openwin.org/mike/presentations/hierarchy/hierarchy.html
Regrads! -----Original Message----- From: mel list_php [mailto:[EMAIL PROTECTED] Sent: Tuesday, August 30, 2005 9:01 AM To: mysql@lists.mysql.com Subject: hierarchical db/depth? hi! I'm still trying to organize an hierachical db (I saw the last article on mysql.com: http://dev.mysql.com/tech-resources/articles/hierarchical-data.hml). I began working with what the author calls "adjency list model" (I think the nested set model is a bit too complex for what I want to do.In addition I found an equivalent schema in an other application which is close to mine....and working fine) Basically, I have a table term (term_id, name), relation (relation_id,term_id1,term_id2,type_id) and a last table to identify the relations type id, relation_type (type_id,type_name). I can retrieve all the info I need with that query: SELECT t1.term_id2 AS lev0, term0.name AS parent0, trel1.type_name AS rel1, t1.term_id1 AS lev1, term1.name AS parent1, trel2.type_name AS rel2, t2.term_id1 AS lev2, term2.name AS parent2, trel3.type_name AS rel3, t3.term_id1 AS lev3, term3.name AS parent3 FROM relation AS t1 LEFT JOIN relation_type AS trel1 USING ( type_id ) LEFT JOIN term AS term0 ON ( t1.term_id2 = term0.term_id ) LEFT JOIN relation AS t2 ON t2.term_id2 = t1.term_id1 LEFT JOIN relation_type AS trel2 USING ( type_id ) LEFT JOIN term AS term1 ON ( t2.term_id2 = term1.term_id ) LEFT JOIN relation AS t3 ON t3.term_id2 = t2.term_id1 LEFT JOIN relation_type AS trel3 USING ( type_id ) LEFT JOIN term AS term2 ON ( t3.term_id2 = term2.term_id ) LEFT JOIN term AS term3 ON t3.term_id1 = term3.term_id WHERE t1.term_id2 =1 It's just adding a new sub-part to the query for each level. This is working fine on my data sample, because I know that I have exactly 4 levels of depth. I would like to know if there is a way to have a kind of "auto-extension" of the query if there is for example a fifth level? Thanks for any help or tip, melanie _________________________________________________________________ Be the first to hear what's new at MSN - sign up to our free newsletters! http://www.msn.co.uk/newsletters -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
