Database: donor
Question: What percentage of projects that have not received a cash donation have received a portion of a donation included corporate sponsored giftcard?
SQL: SELECT CAST(SUM(CASE WHEN payment_included_campaign_gift_card = 't' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(donationid) FROM donations WHERE payment_method = 'no_cash_received'