I think this should work for you. Basically, since you don't have a primary key to join on, you'll need to perform a LEFT JOIN
on all your other fields. If any are different, then the NULL
check will be true:
SELECT t.*
FROM tbl_A_temp t
LEFT JOIN tbl_A a ON
t.field1=a.field1 AND t.field2=a.field2 AND ...
WHERE a.field1 IS NULL
I've also seen others use CHECKSUM
, but have run into issues myself with it returning false positives.