Selection did not return a value, and no default was provided while executing "db_string comment_attachment_type_get { select file_type from comments where comment_id = :comment_id }" (procedure "ad_static_comments_get_attachment" line 10) invoked from within "ad_static_comments_get_attachment {}" ("eval" body line 1) invoked from within "eval $proc [list $conn] $args" invoked from within "ad_return -code error -errorcode $errorCode -errorinfo $errorInfo $error"