look this:
http://dev.mysql.com/tech-resources/articles/hierarchical-data.html is for mysql but aplies to every sql DB ----- Mensaje original ---- De: Michael Chen <vancouver.mich...@gmail.com> Para: sqlite-users@sqlite.org Enviado: mié, octubre 14, 2009 10:40:45 AM Asunto: [sqlite] how to represent a tree in SQL Dear there, I am developing a numerical application, where a single rooted dynamic tree is the main data structure. I intended to use SQLite for this purpose and also for other data as well. However I have no reference how to represent a tree using tables. I need these functionalities: (1) basic tree: single root, multi-levels, arbitrary number of branches, index each node, index each path (from root to a leaf), lookup parent, lookup descendants (2) dynamics: delete a path, add a path; maintain parent and descendants table; maintain history of tree; lookup history (3) each node has lots of matrix and vectors, which will be updated with dynamics, and should be tracked As you see, it is nontrivial to write a tree structure to support all these functions, while keep the code clean and neat. That's why I want to use SQLite to keep things straight. Is there a good reference on this? Michael Chen _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users Yahoo! Cocina Encontra las mejores recetas con Yahoo! Cocina. http://ar.mujer.yahoo.com/cocina/ _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
