Thanks for the example, it was exactly what I was looking for. On Friday, July 21, 2017 at 10:47:16 AM UTC-6, Mike Bayer wrote: > > On Fri, Jul 21, 2017 at 11:40 AM, Nathan Mooth <nat.d...@gmail.com > <javascript:>> wrote: > > So I have a tree-like data structure that I need to store in a way so > that I > > can see all children or all parents of a query as well as their relative > > depth from the query item. In the past I have been using the closure > table > > method demonstrated in this blog post, however now that I am switching > to > > sqlAlchemy I am wondering if there is a better way to do this. So > basically > > I am trying to figure out how to run a series of inserts on my closure > table > > whenever an item is added to the main table, as well as what would be > the > > best way to load the child or parent items of a query. > > you'd likely want to use the same approaches illustrated in the nested > sets example at > > http://docs.sqlalchemy.org/en/latest/_modules/examples/nested_sets/nested_sets.html > > - basically intercept before_insert(), or after_insert(), the run the > additional SQL you need on the given connection within the flush > process. The query approach is also illustrated there. > > If you're just going for in-memory, "load a node, then access > node.children", and you don't need elaborate cross-depth searching and > set operations, then all of these approaches are far too complicated, > just use adjacency list. > > > > > > > > > -- > > SQLAlchemy - > > The Python SQL Toolkit and Object Relational Mapper > > > > http://www.sqlalchemy.org/ > > > > To post example code, please provide an MCVE: Minimal, Complete, and > > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > > description. > > --- > > You received this message because you are subscribed to the Google > Groups > > "sqlalchemy" group. > > To unsubscribe from this group and stop receiving emails from it, send > an > > email to sqlalchemy+...@googlegroups.com <javascript:>. > > To post to this group, send email to sqlal...@googlegroups.com > <javascript:>. > > Visit this group at https://groups.google.com/group/sqlalchemy. > > For more options, visit https://groups.google.com/d/optout. >
-- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
