9.1.6. Bit-Field Literals

Bit-field values can be written using b'value' or 0bvalue notation. value is a binary value written using zeros and ones.

Bit-field notation is convenient for specifying values to be assigned to BIT columns:

mysql> CREATE TABLE t (b BIT(8));mysql> INSERT INTO t SET b = b'11111111';mysql> INSERT INTO t SET b = b'1010';mysql> INSERT INTO t SET b = b'0101';

Bit values are returned as binary values. To display them in printable form, add 0 or use a conversion function such as BIN(). High-order 0 bits are not displayed in the converted value.

mysql> SELECT b+0, BIN(b+0), OCT(b+0), HEX(b+0) FROM
        t;+------+----------+----------+----------+| b+0  | BIN(b+0) | OCT(b+0) | HEX(b+0) |+------+----------+----------+----------+|  255 | 11111111 | 377      | FF       ||   10 | 1010     | 12       | A        ||    5 | 101      | 5        | 5        |+------+----------+----------+----------+

Bit values assigned to user variables are treated as binary strings. To assign a bit value as a number to a user variable, use CAST() or +0:

mysql> SET @v1 = 0b1000001;mysql> SET @v2 = CAST(0b1000001 AS UNSIGNED), @v3 =
        0b1000001+0;mysql> SELECT @v1, @v2, @v3;+------+------+------+| @v1  | @v2  | @v3  |+------+------+------+| A    |   65 |   65 |+------+------+------+



Spec-Zone.ru - all specs in one place