MySQL in a Nutshell, 2nd Edition

Name

EXPORT_SET()

Synopsis

EXPORT_SET(number, on, off[, separator,[count]])

This function returns a series of strings in order that represent each bit of a given number. The second argument specifies a string to represent bits that are 1 (an on bit), and the third argument specifies a string to represent bits that are 0 (an off bit). The fourth argument may specify a separator, and the last argument may specify a number of bit equivalents to display. The default separator is a comma. Here is an example:

SELECT BIN(4) AS 'Binary Number',
EXPORT_SET(4, 'on', 'off', '-', 8)
AS 'Verbal Equivalent';

+---------------+--------------------------------+
| Binary Number | Verbal Equivalent              |
+---------------+--------------------------------+
| 100           | off-off-on-off-off-off-off-off |
+---------------+--------------------------------+

Notice that the lowest-order bit is displayed first, so the conversion of the binary equivalent of 4 is displayed by EXPORT_SET() in what one might consider reverse order, from right to left: not 100, but 001 (or, as part of 8 bits, 00100000).