UNHEX(str)

MySQL 8.4 🇮🇩 Bahasa Indonesia

Untuk argumen string str, UNHEX(str) menafsirkan setiap pasangan karakter dalam argumen sebagai angka heksadesimal dan mengubahnya menjadi byte yang diwakili oleh angka tersebut. Nilai yang dikembalikan adalah string biner.

Syntax

MYSQL

SELECT UNHEX('4D7953514C');
'MySQL'
SELECT X'4D7953514C';
'MySQL'
SELECT UNHEX(HEX('string'));
'string'
SELECT HEX(UNHEX('1267'));
'1267'

Contoh

Example

The characters in the argument string must be legal hexadecimal digits: '0' .. '9', 'A' .. 'F', 'a' .. 'f'. If the argument contains any nonhexadecimal digits, or is itself NULL, the result is NULL:

MYSQL

SELECT UNHEX('4D7953514C');
'MySQL'
SELECT X'4D7953514C';
'MySQL'
SELECT UNHEX(HEX('string'));
'string'
SELECT HEX(UNHEX('1267'));
'1267'

Example 2

A NULL result can also occur if the argument to UNHEX() is a BINARY column, because values are padded with 0x00 bytes when stored but those bytes are not stripped on retrieval. For example, '41' is stored into a CHAR(3) column as '41 ' and retrieved as '41' (with the trailing pad space stripped), so UNHEX() for the column value returns X'41'. By contrast, '41' is stored into a BINARY(3) column as '41\0' and retrieved as '41\0' (with the trailing pad 0x00 byte not stripped). '\0' is not a legal hexadecimal digit, so UNHEX() for the column value returns NULL.

MYSQL

SELECT UNHEX('GG');
+-------------+
| UNHEX('GG') |
+-------------+
| NULL        |
+-------------+

SELECT UNHEX(NULL);
+-------------+
| UNHEX(NULL) |
+-------------+
| NULL        |
+-------------+