error from eduPersonScopedAffiliation in IDP 3.1.2

[Peter Schober]

* Rob Ansaldo <rlansaldo at amherst.edu> [2015-09-02 17:32]:
> Modify the SQL query used to derive the attribute using the COALESCE function, something like this:
> 
> <![CDATA[
>   SELECT COALESCE(myAttribute, ‘NONE’) AS myAttribute FROM table WHERE uid = ‘${requestContext.principalName}’
> ]]> 
> 
> this substitutes the string NONE where the user has a NULL for this
> particular attribute - this keeps the error from occurring since it
> is no longer empty. Then to keep the NONE from being released, add
> an attribute filter policy to block the release if it is set to
> NONE:

You're likely selecting more than that one myAttribute in that query,
right (and you wouldn't want to lose the results because of a NULL
myAttribute), right? Otherwise you could simply add a not-NULL check
to the WHERE clause, which would save you to check for the replacement
string (and prevent release) later in the filter.
-peter