Compare a set of database table data on different servers

How may you validate, that data on different databases equal each other?
Execute the following (mysql) query on each database. You will get an MD5 string which is easily to be compared.

SELECT MD5( SUM( ch ) )
FROM (
SELECT crc32( MD5( CONCAT_WS( ',',
field1, field2, field3
) ) ) AS ch
FROM tablename
WHERE field0 = 3
)a

PS: Insert into the field list only fields which should be compared.
E.g. Do not include auto increment or timestamp/date columns if they are allowed to be different on each database!