CRC32

Syntax

Current

CRC32([par,]expr)

< 10.8

CRC32(expr)

Description

Computes a cyclic redundancy check (CRC) value and returns a 32-bit unsigned value. The result is NULL if the argument is NULL. The argument is expected to be a string and (if possible) is treated as one if it is not.

Current

Uses the alternate Castagnoli polynomia.

Often, CRC is computed in pieces. To facilitate this, there's an optional parameter: CRC32('MariaDB')=CRC32(CRC32('Maria'),'DB').

< 10.8

Uses the ISO 3309 polynomial that used by zlib and many others.

Examples

Current

SELECT CRC32(CRC32('Maria'),'DB');
+----------------------------+
| CRC32(CRC32('Maria'),'DB') |
+----------------------------+
|                 4227209140 |
+----------------------------+

< 10.8

SELECT CRC32('MariaDB');
+------------------+
| CRC32('MariaDB') |
+------------------+
|       4227209140 |
+------------------+

SELECT CRC32('mariadb');
+------------------+
| CRC32('mariadb') |
+------------------+
|       2594253378 |
+------------------+

See Also

• CRC32C()

_{This page is licensed: GPLv2, originally from fill_help_tables.sql}