Perhaps you can try other methods to model parent-child relationship? These are related to Closure Table but also talk about other methods:
http://stackoverflow.com/questions/192220/what-is-the-most-efficient-elegant-way-to-parse-a-flat-table-into-a-tree http://dirtsimple.org/2010/11/simplest-way-to-do-tree-based-queries.html http://karwin.blogspot.co.uk/2010/03/rendering-trees-with-closure-tables.html<http://karwin.blogspot.co.uk/2010/03/rendering-trees-with-closure-tables.html> Storing Hierarchical Data in a Database (Adjacency List, Modified Preorder Tree Traversal and more reading materials at the end of the article) http://www.sitepoint.com/hierarchical-data-database/ Adjacency List, Materialized Path, Nested Set and Closure Table http://www.slideshare.net/billkarwin/models-for-hierarchical-data MPTT https://groups.google.com/forum/?fromgroups=#!topic/web2py/Bw792rYt_nM On Monday, 4 March 2013 22:08:49 UTC, 黄祥 wrote: > > hi, > > i want to show parent child tree using table that have self-reference. > actually i've tried the self-reference query, but the result is not i > expected, is there any idea for this? > > for example: > *db.py* > db.define_table('category', > Field('category', length=10, notnull=True, unique=True), > Field('parent', 'reference category'), > format='%(category)s') > > db.category.parent.requires=IS_EMPTY_OR(IS_IN_DB(db, 'category.category')) > > db.category.bulk_insert([{'category' : 'Monitor'}, > {'category' : 'Keyboard'}, > {'category' : 'Monitor LCD', 'parent' : '1'}, > {'category' : 'Monitor LED', 'parent' : '1'}, > {'category' : 'Keyboard Cable', 'parent' : '2'}, > {'category' : 'Keyboard Gaming', 'parent' : '2'}, > {'category' : 'Keyboard Wireless', 'parent' : > '2'}]) > > *output i expected * > Keyboard > - Keyboard Cable > - Keyboard Gaming > - Keyboard Wireless > Monitor > - Monitor LCD > - Monitor LED > > thank you so much in advance > -- --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
