another way is to store the original hierarchy in a sql database (in the form: id, parent_id, name, level) and in the Lucene index store the complete hierarchy (from root to leave node) for each document in one field using the ids of the sql database. In that way you can get documents at any level of the hierarchy. You can use the sql database to dynamically expand the tree by building facet queries to fetch document collections of child-nodes.
Johannes from the root level down to leave node in one field "1 13 32 42 23 12" 2012/1/23 <dar...@ontrenet.com>: > > On Mon, 23 Jan 2012 14:33:00 -0800 (PST), Yuhao <nfsvi...@yahoo.com> > wrote: >> Programmatically, something like this might work: for each facet field, >> add another hidden field that identifies its parent. Then, program >> additional logic in the UI to show only the facet terms at the currently >> selected level. For example, if one filters on "cat:electronics", the > new >> UI logic would apply the additional filter "cat_parent:electronics". > Can >> this be done? > > Yes. This is how I do it. > >> Would it be a lot of work? > No. Its not a lot of work, simply represent your hierarchy as parent/child > relations in the document fields and in your UI drill down by issuing new > faceted searches. Use the current facet (tree level) as the parent:<level> > in the next query. Its much easier than other suggestions for this. > >> Is there a better way? > Not in my opinion, there isn't. This is the simplest to implement and > understand. > >> >> By the way, Flamenco (another faceted browser) has built-in support for >> hierarchies, and it has worked well for my data in this aspect (but less >> well than Solr in others). I'm looking for the same kind of > hierarchical >> UI feature in Solr.
