I just wanted to share this query for anyone who is updating their site from SimpleFields to Advanced Custom Fields:
SET @key_from = " _simple_fields_fieldGroupID_3_fieldID_0_numInSet_0";
SET @key_to = "hero_title";
UPDATE wp_postmeta a,
(
SELECT
meta_id,post_id,meta_key,meta_value
FROM wp_postmeta
WHERE meta_key = @key_from
AND meta_value <> ''
)
b SET a.meta_value = b.meta_value
WHERE a.meta_key = @key_to
and a.meta_value = ''
and a.post_id = b.post_id
All you need to do is find the Simple Fields key and map it to the corresponding ACF key.