9.1.3. Hexadecimal Values
MySQL supports hexadecimal values. In numeric contexts, these
act like integers (64-bit precision). In string contexts, these
act like binary strings, where each pair of hex digits is
converted to a character:
mysql> SELECT x'4D7953514C';
-> 'MySQL'
mysql> SELECT 0xa+0;
-> 10
mysql> SELECT 0x5061756c;
-> 'Paul'
The default type of a hexadecimal value is a string. If you want
to ensure that the value is treated as a number, you can use
CAST(... AS UNSIGNED):
mysql> SELECT 0x41, CAST(0x41 AS UNSIGNED);
-> 'A', 65
The x'hexstring'
syntax is based on standard SQL. The 0x
syntax is based on ODBC. Hexadecimal strings are often used by
ODBC to supply values for BLOB columns.
You can convert a string or a number to a string in hexadecimal
format with the HEX() function:
mysql> SELECT HEX('cat');
-> '636174'
mysql> SELECT 0x636174;
-> 'cat'
