User Guide

Handling runtime exceptions with ColdFusion tags 335
<cftry>
<!--- Inner Try Block --->
<cftry>
<!--- Try to query the main database and set a caller variable to the result -
-->
<cfquery Name = "getUser" DataSource="cfdocexamples">
SELECT *
FROM Employee
WHERE LastName = ’#attributes.EmpName#’
</cfquery>
<cfset caller.getEmpsResult = getuser>
<!--- If the query failed with a database error, check the error type
to see if the database was found --->
<cfcatch type= "Database">
<cfif (cfcatch.SQLState IS "S100") OR (cfcatch.SQLState IS
"IM002")>
<!--- If the database wasn't found, try the backup database --->
<!--- Use a third-level Try block --->
<cftry>
<cfquery Name = "getUser" DataSource="cfdocexamplesBackup">
SELECT *
FROM Employee
WHERE LastName = ’#attributes.EmpName#’
</cfquery>
<cfset caller.getEmpsResult = getuser>
<!--- If still get a database error, just return to the calling page
without setting the caller variable. There is no cfcatch body.
This might not be appropriate in some cases.
The Calling page ends up handling this case as if a match was not
found --->
<cfcatch type = "Database" />
<!--- Still in innermost try block. Rethrow any other errors to the next
try block level --->
<cfcatch type = "Any">
<cfrethrow>
</cfcatch>
</cftry>
<!--- Now in second level try block.
Throw all other types of Database exceptions to the next try
block level --->
<cfelse>
<cfrethrow>
</cfif>
</cfcatch>
<!--- Throw all other exceptions to the next try block level --->
<cfcatch type = "Any">
<cfrethrow>
</cfcatch>
</cftry>
<!--- Now in Outermost try block.