Displaying Nested Sets

Question

Hello~
I am just starting to use the nested set model for storing hierarchical data in a database, and while I understand the concept, I am not at all sure how to actually display the data in, say, an unordered list! Right now, I am using the following query to retrieve my list:
SELECT
        node.pageName
    FROM
        admin_nav AS node,
        admin_nav AS parent
    WHERE
        node.lft BETWEEN parent.lft AND parent.rght
        AND parent.pageName = 'Assessment'
    ORDER BY
        node.lft
It outputs correctly if I cfdump it, but I am not sure how to create a loop that would put the <ul> and <li> tags in the correct places. I have searched for some kind of tutorial about this, but no luck! Any help would be appreciated. Thanks!
KC

Answer 1

OK, I think I have got it all figured out, and I thought I would post my solution! Thanks to everyone for your help!
I added a new table to my database to hold any special formatting tags for a given depth of the list (ie, I want my 1st level items to be enclosed in <h2></h2> tags).
Query:
    SELECT
        o.pageName,
        o.depth,
        ant.specialTag
    FROM
        ADMIN_nav_tag AS ant
        RIGHT JOIN
                SELECT TOP (100) PERCENT
                    node.pageName,
                    (COUNT(parent.pageName) - 1) AS depth
                FROM
                    admin_nav AS node,
                    admin_nav AS parent
                WHERE
                    node.lft BETWEEN parent.lft AND parent.rght
                    AND node.pageName <> 'Home'
                GROUP BY
                    node.pageName,
                    node.lft
                ORDER BY
                    node.lft
        AS o
        ON ant.depth = o.depth
Output:
<div id="navBar">
    <ul>
        <Cfset count = 0 />
        <cfoutput query="getNav" group="depth">
            <cfset liTag = '' />
            <cfif specialTag NEQ ''>
                <cfset liTag = '<' & #specialTag# & '>' />
            </cfif>
            <cfoutput>
                <Cfset fdepth = getNav.depth[getNav.currentRow + 1 ] />
                <cfif lengthcount eq 1>
                    <li>#liTag##pagename##replaceNoCase(liTag, '<', '</')#</li>
                <cfelse>
                    <li>#liTag##pagename##replaceNoCase(liTag, '<', '</')#
                    <cfif count lt lengthCount -1>
                        <Cfif fdepth gt depth>
                            <ul>
                        <cfelse>
                            </li>
                        </Cfif>
                        <cfif fdepth lt depth>
                            #repeatString('</ul></li>',depth-fdepth)#
                        </cfif>
                    <cfelse>
                        </li>
                    </cfif>
                    <Cfset count = count + 1 />
                </cfif>
            </cfoutput>
        </cfoutput>
    </ul>
</div>