Path strings:
Id | ParentId | PathString | Path Identification String | Depth
---+----------+------------+--------------------------------+------
87 | 2 | /87/ | countries | 2
88 | 87 | /87/88/ | countries/belgium | 3
89 | 87 | /87/89/ | countries/netherlands | 3
91 | 89 | /87/89/91/ | countries/netherlands/business | 4
92 | 89 | /87/89/92/ | countries/netherlands/economy | 4
90 | 87 | /87/90/ | countries/germany | 3