Auto action conditions Special Case

I have an auto actioned conditioned to fire according to:

[cb_condition01] equals to yes

cb_condition01 is a query fieldtype which co tains the query below.. somehow the auto action above does not fire eventhough it is showing 'yes'

SELECT case when datediff(DATE_ADD(NOW(), INTERVAL 100 DAY),lastvisitDate) >91 then 'yes' else 'no' end FROM jos_users where username= '[username]'

Enable debug mode and maximum error reporting in Joomla global configuration then edit your action and under Parameters enable debugging. Now test your action and it'll output the condition and the values it tried checking if it failed.