SQL Order - matching results to a list

Question

I have a list which I query, matchin the list on the camp_uid. The problem is that I want to display the results in the same order as the list was originally compiled, which is not in numeric order. One option is to set up a loop on the original list values, then use a query over query to obtain the results that are appropriate to that camp_uid, but there must be a better way? I search the ORDER command, there does not seem to be anything in place to make it keep the order of the supplied list in the IN statement.
Anybody have any better ideas than my query over query? I am a lilttle concerned over the the performance being forced to run multiple queries over data that I already have, even if they are in a Query over Query
<CFQUERY name="GetCamp" DATASOURCE="#datasource#">
    SELECT camp_uid,camp_title,camp_text,camp_image_type
    FROM campaigns
    WHERE camp_uid IN (
<cfqueryparam value="#session.camp_list#" cfsqltype="CF_SQL_INTEGER" list="true">
</CFQUERY>
Thanks
Mark

Answer 1

You might try adding a column to your query based on the order the camp ids appear in the list.
To items to consider:
1. This code is not tested.
2. You should validate that your session.camp_list variable contains only integers, else you are vulnerable to a SQL injection attack.
3. This code assume that your list does not contain any duplicate values.
<CFQUERY name="GetCamp" DATASOURCE="#datasource#">
    SELECT camp_uid,camp_title,camp_text,camp_image_type,
        CASE       
        <!--- loop over list and create an order value for each camp, this assumes that list does not contain any duplicates --->
        <cfloop from="1" to="#ListLen(session.camp_list)#" index="listIdx">
            WHEN camp_uid = #ListGetAt(session.camp_list ,listIdx)#
                THEN #listIdx#
        </cfloop>
        END AS camp_order
    FROM campaigns
    WHERE camp_uid IN ( <cfqueryparam value="#session.camp_list#" cfsqltype="CF_SQL_INTEGER" list="true"> )
    ORDER BY camp_order;
</CFQUERY>
Assume that your session.camp_list variable contains "23,17,5" the query qenerated should look like:
SELECT camp_uid,camp_title,camp_text,camp_image_type,
    CASE
        WHEN camp_uid = 23
            THEN 1
        WHEN camp_uid = 17
            THEN 2
        WHEN camp_uid = 5
            THEN 3   
    END AS camp_order
FROM campaigns
WHERE camp_uid IN ( 23,17,5 )
ORDER BY camp_order;
Message was edited by: JR \"Bob\" Dobbs.