Muenchian grouping difficulties

Question

I am building a Sharepoint search results page to find the answers to questions asked in a 3rd party tool.
I have a bdc connection to their sql db.
I am crawling just one one table in the db.
I need to group question and answer results together using the muenchian method using several columns in the same table.
I cant change the db so I have to pull the results together in search to be something meaningful.
This table contains all the entries of questions asked and answers given.
I have to tie them together for us using search as the application to present the Q&A
overview of the data:
Each record returned in the core search results has an:
title - this is the question or the answer
activityid(int) - unique id of the entry
activitytypeid(int) - these identify if its a Q or A / 79 or 82
parentid(int) - this value contains the activityid of the original question - if the record is the original question, it will have a value of 0 for this column
isanswer(boolean) true or nothing (this is sort of redundant and does the same as activitytypeid but I was not sure if I could use it to help with the grouping)
Review
activitype id is either:
79 - question being asked - this will have a parentid of 0
or
82 - answer to question - this will have a parent id matching the activityid of the original question
I am trying but without much success to get my search results grouped/sorted to have the question returned first. In the example below it would be activityid 19142 and the answers to the question indented underneath with all grouped in a set
any help in reviewing my hack at this or examples would be great.
I am just trying to understand xsl and this has been a big learning curve. I have a long way to go and most certainly have jumped into the deep end on this.
raw xml of results i currently get without formatting the results
  <All_Results>
    <Result>
      <id>1</id>
      <title>Answer 1</title>
      <isanswer>true</isanswer>
      <parentid>19142</parentid>
      <activitytype>82</activitytype>
      <activityid>19146</activityid>
    </Result>
    <Result>
      <id>2</id>
      <title>Original Question</title>
       <isanswer></isanswer>
      <parentid>0</parentid>
      <activitytype>79</activitytype>
      <activityid>19142</activityid>
    </Result>
    <Result>
      <id>3</id>
      <title>Answer 2</title>
       <isanswer>true</isanswer>
      <parentid>19142</parentid>
      <activitytype>82</activitytype>
      <activityid>19199</activityid>
    </Result>
    <Result>
      <id>4</id>
      <title>another Question</title>
       <isanswer></isanswer>
      <parentid>0</parentid>
      <activitytype>79</activitytype>
      <activityid>19200</activityid>
    <Result>
    <Result>
      <id>5</id>
      <title>and another Question</title>
       <isanswer></isanswer>
      <parentid>0</parentid>
      <activitytype>79</activitytype>
     <activityid>19254</activityid>
    <Result>
    <Result>
      <id>6</id>
      <title>Answer</title>
       <isanswer>true</isanswer>
      <parentid>19200</parentid>
      <activitytype>82</activitytype>
   <activityid>19265</activityid>
    </Result>
  </All_Results>
The output I am looking for would have all answers grouped with the corresponding question
here is my attempts to make this work in my search core results xslt.
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:param name="isanswer" />
    <xsl:param name="parentid" />
    <xsl:param name="activityid" />
 <xsl:param name="activitytypeid" />
 <xsl:key name="Questions" match="Result" use="activityid" />
 <xsl:key name="mashupid" match="Result"  use="concat(isanswer, ' ', parentid, ' ', activityid)" />
   <xsl:template match="All_Results"> 
     <xsl:variable name="QuestionsVar" select="key('Questions', activityid)" />
  <xsl:for-each select="$QuestionsVar[generate-id() = generate-id(key('mashupid', concat(isanswer, ' ', parentid, ' ', activityid))[1])]">
 <xsl:text>ActivityId </xsl:text>
 <xsl:value-of select="activityid" /><br />
 <xsl:text>Marked as Answer to: </xsl:text>
 <xsl:value-of select="parentid" /><br />
 <xsl:text>Variablevalue: </xsl:text>
 <xsl:value-of select="@QuestionsVar" /><br />
    <xsl:text>IsAnswer: </xsl:text>
    <xsl:value-of select="isanswer" /><br />
 <xsl:text>Title: </xsl:text>
 (<xsl:value-of select="title" />)<br />
  </xsl:for-each><br /><br />
   </xsl:template>
</xsl:stylesheet>
Thanks
Eric
Eric

Answer 1

I am confused that whether we can apply
muenchian grouping for two different fields value or not.
I have implemented muenchian
grouping for one field value  in custom xslt and it is working fine.
But in the case for applying two different field value ,I am in doubt.
Can anyone provide me some link whether muenchian
grouping is applying on two different fields value .
Prakash