> I was wondering which is the best way to model a tree-looking > structure with SqlAlchemy.
I've spent a lot of time dealing with different types of hierarchies in SQLAlchemy lately... One way is to use the "nested sets" model. This does a decent job at modelling hierarchies, at least as long as you don't have the same leaf in the tree at multiple locations. Some links describing nested sets: http://dev.mysql.com/tech-resources/articles/hierarchical-data.html http://en.wikipedia.org/wiki/Nested_set_model And here is a decent example of how to do this in sqlalchemy: http://www.sqlalchemy.org/trac/browser/examples/adjacency_list/adjacency_list.py The 'classic' way is the 'adjacency list' model. Here is an sqlalchemy example: http://www.sqlalchemy.org/trac/browser/examples/adjacency_list/adjacency_list.py You can also look up another pattern that seems to get labelled as 'materialized path'. No clean sqlalchemy example I know of, but the concept is easy: http://www.google.ca/search?q=(hierarchical+OR+hierarchy)+materialized+path Good luck! Russ -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
