Update MP SELECT Ancestors.md

Author: pchemguy

MP SELECT Ancestors.md

@@ -80,7 +80,20 @@ WITH
 SELECT * FROM ancestors;
 ~~~
 
-Blocks *json_nodes* through *tops* constitute the same prologue as [before](select-desc#prologue). The *prefixes* block retrieves node prefixes from the *categories* table (alternatively, prefixes could be calculated from the input by stripping the last path parts). *json_prefixes* prepares "nested doll" JSON objects, and the *ancestors* block generates ancestor lists. The last block temporarily escapes any periods in names by replacing them with '^#^'  at the beginning and performing the inverse replacement at the end.
+Blocks *json_nodes* through *tops* constitute the same prologue as [before](select-desc#prologue). The *prefixes* block retrieves node prefixes from the *categories* table (alternatively, the query could incorporate the [path splitting template](../patterns/split-dsv#Split-Path)). *json_prefixes* prepares "nested doll" JSON objects. The *ancestors* block generates ancestor lists, temporarily replacing any periods in names with '^#^'  at the beginning and reversing it at the end. Note that if the input contains multiple paths with a shared prefix, the *asc_path* will have duplicate values.
+
+**Output**
+
+| ascii_id | asc_path                  |
+|----------|---------------------------|
+| 0FDAF2C8 | tcl/                      |
+| 0FDAF2C8 | tcl/compat/               |
+| BE0A8514 | tcl/                      |
+| BE0A8514 | tcl/pkgs/                 |
+| BE0A8514 | tcl/pkgs/thread2.8.7/     |
+| BE0A8514 | tcl/pkgs/thread2.8.7/tcl/ |
+
+---
 
 A similar query splits provided paths directly:
 
@@ -105,14 +118,29 @@ WITH
         FROM levels
     ),
     ancestors AS (
-        SELECT jo.id,
+        SELECT min(jo.id) AS id,
             replace(replace(substr(fullkey, 3), '.', '/'), '^#^', '.') || '/' AS asc_path
         FROM
             json_objs AS jo,
             json_tree(replace(jo.json_obj, '.', '^#^')) AS terms
         WHERE terms.parent IS NOT NULL
+		GROUP BY asc_path
+		ORDER BY id, asc_path
     )
 SELECT * FROM ancestors;
 ~~~
 
-This query splits paths as provided and no longer accesses the *categories* table. The _nodes_ block also labels paths with array element id generated by _json_each_ instead of *ascii_id*.
+This query splits paths as provided and no longer accesses the *categories* table. Additionally, the *nodes* block labels paths with array element id (instead of *ascii_id*) generated by *json_each*, and the *ancestors* block removes duplicate terms.
+
+**Output**
+
+| id | asc_path                         |
+|----|----------------------------------|
+| 1  | tcl/                             |
+| 1  | tcl/compat/                      |
+| 1  | tcl/compat/zlib1/                |
+| 2  | tcl/pkgs/                        |
+| 2  | tcl/pkgs/thread2.8.7/            |
+| 2  | tcl/pkgs/thread2.8.7/tcl/        |
+| 2  | tcl/pkgs/thread2.8.7/tcl/cmdsrv/ |
+