11.12. Bit Functions

Table 11.16. Bitwise Functions

NameDescription
BIT_COUNT()Return the number of bits that are set
&Bitwise AND
~Invert bits
|Bitwise OR
^Bitwise XOR
<<Left shift
>>Right shift

MySQL uses BIGINT (64-bit) arithmetic for bit operations, so these operators have a maximum range of 64 bits.

  • |

    Bitwise OR:

    mysql> SELECT 29 | 15;
            -> 31
    

    The result is an unsigned 64-bit integer.

  • &

    Bitwise AND:

    mysql> SELECT 29 & 15;
            -> 13
    

    The result is an unsigned 64-bit integer.

  • ^

    Bitwise XOR:

    mysql> SELECT 1 ^ 1;
            -> 0
    mysql> SELECT 1 ^ 0;
            -> 1
    mysql> SELECT 11 ^ 3;
            -> 8
    

    The result is an unsigned 64-bit integer.

  • <<

    Shifts a longlong (BIGINT) number to the left.

    mysql> SELECT 1 << 2;
            -> 4
    

    The result is an unsigned 64-bit integer. The value is truncated to 64 bits. In particular, if the shift count is greater or equal to the width of an unsigned 64-bit number, the result is zero.

  • >>

    Shifts a longlong (BIGINT) number to the right.

    mysql> SELECT 4 >> 2;
            -> 1
    

    The result is an unsigned 64-bit integer. The value is truncated to 64 bits. In particular, if the shift count is greater or equal to the width of an unsigned 64-bit number, the result is zero.

  • ~

    Invert all bits.

    mysql> SELECT 5 & ~1;
            -> 4
    

    The result is an unsigned 64-bit integer.

  • BIT_COUNT(N)

    Returns the number of bits that are set in the argument N.

    mysql> SELECT BIT_COUNT(29), BIT_COUNT(b'101010');
            -> 4, 3
    
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