Merging two lists?

Question

I need to know if it is possible to merge two lists using coldfusion.  I have one list uploaded to the site then they want the ability to upload a second list with may have additional fields and/or different number of records.  Need to know if this is possible, how to do it if it is, and how the two list will match up.  Thanks in advance for the help.

Answer 1

Right, well in that case this isn't really anything to do with merging lists per se, hence the confusion I believe. Technically, you'd do this:
<cfset newData = fileOpen("c:\newlist.csv","read") />
<!--- Loop through your file, one line at a time --->
<cfloop condition="NOT fileIsEof(newData)">
  <!--- Create a string of the line, this is a true list --->
  <cfset thisLine = fileReadLine(newData) />
  <!--- Get the elements of the list we want for the query --->
  <cfset thisForename = listGetAt(thisLine,1) />
  <cfset thisSurname = listGetAt(thisLine,2) />
  <!--- Check if this person exists --->
  <cfquery datasource/username/password name="qCheckExists">
    SELECT    id
    FROM      mytable
    WHERE     firstname = <cfqueryparam cfsqltype="cf_sql_varchar" value="#thisForename#" />
    AND       surname = <cfqueryparam cfsqltype="cf_sql_varchar" value="#thisSurname"#" />
  </cfquery>
  <!--- If we found rows, update --->
  <cfif qCheckExists.RECORDCOUNT eq 1 >
    <cfquery datasource/username/password>
        UPDATE   mytable
        SET      forename = <listGetAt,thisLine, FIELD>,
                 surname = <listGetAt,thisLine, FIELD>,
                 address = <listGetAt,thisLine, FIELD>,
                     etc etc etc
        WHERE    id = qCheckExists.id
    </cfquery>
  <cfelseif qCheckExists.RECORDCOUNT >
    <!--- here you found more than one matching row, up to you what to do --->
  <cfelse>
    <!--- here you didn't find a match, so do an insert --->
  </cfif>
</cfloop>
<cfset fileClose(newData) />
That's how you'd do it on a technical level, the Business decisions are yours. What if it's John not Jon? What if it's Jonathan? That's not a programming problem, that's up to you to decide - I'm not sure we can help you there.
O.