WordPress database error: [Incorrect DATE value: '']SELECT wpdq_posts.*
FROM wpdq_posts INNER JOIN wpdq_postmeta ON ( wpdq_posts.ID = wpdq_postmeta.post_id ) INNER JOIN wpdq_postmeta AS mt1 ON ( wpdq_posts.ID = mt1.post_id )
WHERE 1=1 AND (
wpdq_postmeta.meta_key = '_ssf_start'
AND
(
( mt1.meta_key = '_ssf_day' AND CAST(mt1.meta_value AS DATE) BETWEEN '' AND '' )
)
) AND ((wpdq_posts.post_type = 'ssf_event' AND (wpdq_posts.post_status = 'publish')))
GROUP BY wpdq_posts.ID
ORDER BY wpdq_postmeta.meta_value ASC