How to convert PHP's crc32 hash into the MySQL equivalent?

Question

Apparently MySQL\'s CRC32() function returns an unsigned BIGINT, while PHP returns hexadecimal value.

In PHP:

hash(\'crc32\',\'hello world\') == 7813f744

Answer 1

If you have 64-bit platform you can safely use crc32 function in PHP and CRC32 in MySQL. Quick test:

  php > echo crc32('foobar') . "\n";
  2666930069

MySQL:

  >select crc32('foobar');
  +-----------------+
  | crc32('foobar') |
  +-----------------+
  |      2666930069 |
  +-----------------+
  1 row in set (0.00 sec)

Answer 2

It is possible to use the wrapper function that returns the same value as in mysql:

function mysql_compatible_crc32($s) {
    $r = crc32($s);
    if($r<0) {
        return 4294967296+$r;
    }
    return $r;
}