MySQL Tutorial/Encryption Compression Functions/UNCOMPRESS

UNCOMPRESS(string_to_uncompress) uncompresses a string compressed by the COMPRESS() function.

mysql>
mysql> SELECT UNCOMPRESS(COMPRESS("any string"));
+------------------------------------+
| UNCOMPRESS(COMPRESS("any string")) |
+------------------------------------+
| any string                         |
+------------------------------------+
1 row in set (0.00 sec)
mysql>
mysql> SELECT UNCOMPRESS("any string");
+--------------------------+
| UNCOMPRESS("any string") |
+--------------------------+
| NULL                     |
+--------------------------+
1 row in set, 1 warning (0.00 sec)
mysql>