Just found this MySQL snippet for validating EAN numbers.
http://snipplr.com/view.php?codeview&id=17928
I have modified it a bit to suit my requirements (namely totally corrupted EAN data).
PLAIN TEXT
SQL:
SELECT ean
FROM products
WHERE
(LENGTH(ean) != 13)
||
(SUBSTRING((10 - ((((
SUBSTRING(ean FROM 2 FOR 1) +
SUBSTRING(ean FROM 4 FOR 1) +
SUBSTRING(ean FROM 6 FOR 1) +
SUBSTRING(ean FROM 8 FOR 1) +
SUBSTRING(ean FROM 10 FOR 1) +
SUBSTRING(ean [...]