Coldfusion cfloop through checkboxes in a cfquery - mysql

Question

I have had a good search through to see if there was something similar to what I am trying to do. Nothing specifically covers it though so without further ado.
I would like my cfloop to work through any of the checked boxes on a search page and display the appropriate results drawn from the database. This is what I have so far:
<cfquery name="joblibrary">
SELECT *
FROM tblJobLibraryRoles JOIN tblJobLibraryCategories
ON tblJobLibraryRoles.category = tblJobLibraryCategories.id
<cfloop list="#form.cbGrade#" index="i">
WHERE grade=<cfqueryparam cfsqltype="cf_sql_varchar" value="#i#"/>
</cfloop>
ORDER BY category, grade, title, heraRef;
</cfquery>
Now it works all fine if only one checkbox is ticked, so I am basically asking can I get this type of CFLOOP to work in the way I've created it, or am I barking up the wrong tree?

Answer 1

You don't need a loop. Just use the sql keyword "in".
where somefield in (
<cfqueryparam
cfsqltype="cf_sql_varchar" value="#form.checkboxfield#"
list="yes">
)
You just have to do something to contend with the situation where no boxes are checked.

Answer 2

IN () is certainly the way to handle this (works with other sql statements as well), but there may be times where you want multiple WHERE conditions that are all entirely defined by variables.
Again, IN () is the solution here, but I'll demonstrate with your query on how to do what you were originally wanting to do.
Simply add a WHERE 0=0 (or 1=1 or anystring=anysamestring. You could even say Where 'trickwhere'='trickwhere' but there's no reason to get wordy with it) and loop over the rest using an AND instead.
<cfquery name="joblibrary">
SELECT * from tblJobLibraryRoles JOIN tblJobLibraryCategories ON tblJobLibraryRoles.category=tblJobLibraryCategories.id
WHERE 0=0
<cfloop list="#form.cbGrade#" index="i">AND grade=<cfqueryparam cfsqltype="cf_sql_varchar" value="#i#"/></cfloop>
ORDER BY category, grade, title, heraRef;
</cfquery>