Bit string operators
Aside from the usual comparison operators, the following operators can be used. Bit string operands of &, |, and # must be of equal length. When bit shifting, the original length of the string is preserved by zero padding (if necessary).
- ||
Description: Connects bit strings.
For example:
1 2 3 4 5
SELECT B'10001' || B'011' AS RESULT; result ---------- 10001011 (1 row)
- &
Description: AND operation between bit strings
For example:
1 2 3 4 5
SELECT B'10001' & B'01101' AS RESULT; result -------- 00001 (1 row)
- |
Description: OR operation between bit strings
For example:
1 2 3 4 5
SELECT B'10001' | B'01101' AS RESULT; result -------- 11101 (1 row)
- #
Description: OR operation between bit strings if they are inconsistent. If the same positions in the two bit strings are both 1 or 0, the position returns 0.
For example:
1 2 3 4 5
SELECT B'10001' # B'01101' AS RESULT; result -------- 11100 (1 row)
- ~
Description: NOT operation between bit strings
For example:
1 2 3 4 5
SELECT ~B'10001'AS RESULT; result ---------- 01110 (1 row)
- <<
Description: binary left shift
For example:1 2 3 4 5
SELECT B'10001' << 3 AS RESULT; result ---------- 01000 (1 row)
- >>
Description: binary right shift
For example:
1 2 3 4 5
SELECT B'10001' >> 2 AS RESULT; result ---------- 00100 (1 row)
The following SQL-standard functions work on bit strings as well as character strings: length, bit_length, octet_length, position, substring, and overlay.
The following functions work on bit strings as well as binary strings: get_bit and set_bit. When working with a bit string, these functions number the first (leftmost) bit of the string as bit 0.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | SELECT 44::bit(10) AS RESULT; result ------------ 0000101100 (1 row) SELECT 44::bit(3) AS RESULT; result -------- 100 (1 row) SELECT cast(-44 as bit(12)) AS RESULT; result -------------- 111111010100 (1 row) SELECT '1110'::bit(4)::integer AS RESULT; result -------- 14 (1 row) |
Casting to just "bit" means casting to bit(1), and so will deliver only the least significant bit of the integer.