CRC32

Syntax

<= MariaDB 10.7

CRC32(expr)

From MariaDB 10.8

CRC32([par,]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.

Uses the ISO 3309 polynomial that used by zlib and many others. MariaDB 10.8 introduced the CRC32C() function, which uses the alternate Castagnoli polynomia.

MariaDB starting with 10.8

Often, CRC is computed in pieces. To facilitate this, MariaDB 10.8.0 introduced an optional parameter: CRC32('MariaDB')=CRC32(CRC32('Maria'),'DB').

Examples

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

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

From MariaDB 10.8.0

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

See Also

• CRC32C()

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