Here is an example of my usual implementation of this:
<cffunction name="getCurrentRecordsCount" access="public" output="false" returntype="any" hint="Get total history records count">
<cfargument name="filters" type="struct" required="false" default="#StructNew()#" hint="Filtering rules">
<cfset var qGetRecordCount = "" />
<cftry>
<cfquery datasource="#variables.dsn#" name="qGetRecordCount">
SELECT COUNT(*) AS cnt FROM ....
</cfquery>
<cfreturn qGetRecordCount.cnt />
<cfcatch type="any">
<cfreturn error(cfcatch.message, cfcatch.detail) />
</cfcatch>
</cftry>
</cffunction>
If you want to handle only database errors, change type to the database.
Errors handling and reporting performed using these three methods:
<cffunction name="error" access="private" output="false" returntype="boolean" hint="Set error status and message">
<cfargument name="message" type="string" required="true" hint="Error message text" />
<cfargument name="detail" type="string" required="false" default="" hint="Error detail text" />
<cfset variables.fError = true />
<cfset variables.fErrorText = arguments.message />
<cfif Len(arguments.detail)>
<cfset variables.fErrorText = variables.fErrorText & " [" & arguments.detail & "]" />
</cfif>
<cfreturn false />
</cffunction>
<cffunction name="gotError" access="public" output="false" returntype="boolean" hint="Return latest error flag state">
<cfreturn variables.fError />
</cffunction>
<cffunction name="getError" access="public" output="false" returntype="string" hint="Return latest error text and reset the flag">
<cfset var txt = variables.fErrorText />
<cfset variables.fError = false />
<cfset variables.fErrorText = "" />
<cfreturn txt />
</cffunction>
Please note that for methods with returntype="void" I use cfset instead of cfreturn:
<cfset error(cfcatch.message, cfcatch.detail) />
So in code I can do the following (cfscript):
// calculate filtered records count
totalLogCount = request.loggingService.getCurrentRecordsCount(filters);
// check if error was thrown
if (request.loggingService.gotError()) {
// report the error details somehow
WriteOutput(request.loggingService.getError());
}