Is there any logical reason to use CFQUERYPARAM in Query of Queries?

Question

I primarily use CFQUERYPARAM to prevent SQL injection. Since Query-of-Queries (QoQ) does not touch the database, is there any logical reason to use CFQUERYPARAM in them? I know that values that do not match the cfsqltype and maxlength will throw an exception, but, these values should already be validated before that and display friendly messages (from a UX viewpoint).

Answer 1

Since Query-of-Queries (QoQ) does not touch the database, is there any logical reason to use CFQUERYPARAM in them? Actually, it does touch the database, the database that you currently have stored in memory. The data in that database could still theoretically be tampered with via some sort of injection from the user. Does that affect your physical database - no. Does that affect the use of the data within your application - yes.

You did not give any specific details but I would err on the side of caution. If ANY of the data you are using to build your query comes from the client then use cfqueryparam in them. If you can guarantee that none of the elements in your query comes from the client then I think it would be okay to not use the cfqueryparam.

As an aside, using cfqueryparam also helps optimize the query for the database although I'm not sure if that is true for query of queries. It also escapes characters for you like apostrophes.

Answer 2

Here is a situation where it's simpler, in my opinion.

<cfquery name="NoVisit" dbtype="query">
select chart_no, patient_name, treatment_date, pr, BillingCompareField
from BillingData
where BillingCompareField not in 
(<cfqueryparam cfsqltype="cf_sql_varchar" 
value="#ValueList(FinalData.FinalCompareField)#" list="yes">)
</cfquery>

The alternative would be to use QuotedValueList. However, if anything in that value list contained an apostrophe, cfqueryparam will escape it. Otherwise I would have to.

Edit starts here

Here is another example where not using query parameters causes an error.

QueryAddRow(x,2);
QuerySetCell(x,"dt",CreateDate(2001,1,1),1);
QuerySetCell(x,"dt",CreateDate(2001,1,11),2);
</cfscript>

<cfquery name="y" dbtype="query">
select * from x
<!--- 
where dt in (<cfqueryparam cfsqltype="cf_sql_date" value="#ValueList(x.dt)#" list="yes">) 
--->
where dt in (#ValueList(x.dt)#)
</cfquery>

The code as written throws this error:

Query Of Queries runtime error.  
Comparison exception while executing IN.
Unsupported Type Comparison Exception: 
The IN operator does not support comparison between the following types: 
Left hand side expression type = "DATE".
Right hand side expression type = "LONG".

With the query parameter, commented out above, the code executes successfully.