Assigning a Variable a Null Value

[Sky Worker]

Hi all. I've got a loop that queries a query outside of the loop. The problem is, the query may get defined, and it may not. But if it gets defined, how do I undefine it for the next loop iteration. Here's some code to wrap your head around it (edited for brevity).

<cfloop>
<cfset queryValue = possibleEmptyString >
<cfif Len(queryValue)>
<cfquery name="queryName" dbtype="query">
select * from something
</cfquery>
</cfif>

<cfif IsDefined("queryName") AND queryName.RecordCount>
error="some error message"
</cfif>
</cfloop>

So, is there not a Function that sets the var to Undefined, or Null, or something? If not, what's the alternative?

Thanks all! 😉

[Dan_Bracuk]

You can set a var to an empty string. For what you appear to be attempting, either cftry/cfcatch, or isQuery() might be useful.

[Sky Worker]

Thanks Dan. But, that won't quite solve my problem.

The problem is that once it becomes a query, I can't reset it back to a String value because I've already turned it into a complex type so IsQuery() it will always return true.

not sure how using a try/catch will solve it either. Am I missing something here?

Thanks for your reply, I appreciate the attentiont to this issue.

[Kronin555 · Accepted solution]

<cfloop>
<cfset queryValue = possibleEmptyString >
<cfset queryName = QueryNew()> <!--- this ensures that queryName is always defined, and is always a query --->
<cfif Len(queryValue)>
<cfquery name="queryName" dbtype="query">
select * from something
</cfquery>
</cfif>

<cfif queryName.RecordCount>
error="some error message"
</cfif>
</cfloop>