Stupid Lucene Tricks: Hierarchies

Mark Leighton Fisher on 2010-07-16T16:09:09

You can search on hierarchies in Lucene if your hierarchy can be represented as a path enumeration (a Dewey-Decimal-like style of encoding a path, like "001.014.003" for the 3rd grandchild of the 14th child of the 1st branch).

For example, a search phrase like:

    hierarchy:001

would return only the direct children of the 1st branch, while:

    hierarchy:001*

would return all descendents of the 1st branch.

To get only the children of a particular node, you specify only that node, like:
```
    hierarchy:001.014.003
```
To get all of the descendents you specify everything that starts with that node:
```
    hierarchy:001.014.003*
```
To get only the descendents after the children (grandchildren, etc.), you specify:
```
    hierarchy:001.014.003.*
```