Aggregate bitfield values with binary OR - sql-server

Question

I have a table with int values being used as bitfields (where each bit is a flag).
Now I would like to aggregate them with a binary operation (in my case OR) so that:
SELECT 1 AS bitfield
INTO #TABLE
UNION ALL SELECT 1 + 2 + 8 + 32
UNION ALL SELECT 2 + 128
UNION ALL SELECT 2 + 32
SELECT AND_AGGR(bitfield) -- Invalid because AND_AGGR doesn't exist
FROM #TABLE
DROP #TABLE
would result in the value 171
What would be a good way to do this that hopefully doesn't require a lot of | and MAX (but if you must, you must)?
I am using MS SQL Server 2008 myself, but solutions on other servers are also of interest.

Answer 1

On MySQL and PostgreSQL you can use BIT_OR.
I don't think SQL Server has this aggregate function.
You could do it with lots of MAX and & as you said:
MAX(x & 1) + MAX(x & 2) + ... + MAX(x & 128)

Answer 2

If you're expecting the result 171, surely you mean binary OR not AND?
In any case, this solution aggregates the values into a variable:
SELECT 1 AS bitfield
INTO #TABLE
UNION ALL SELECT 1 + 2 + 8 + 32
UNION ALL SELECT 2 + 128
UNION ALL SELECT 2 + 32
DECLARE #i int = 0
SELECT #i = #i | bitfield
FROM #TABLE
SELECT #i
DROP TABLE #table
This might not meet your requirements if you want to group the aggregation by another field.
It is also unlikely to perform well on a large table.

Answer 3

In MS SQL Server
DECLARE #agg VARCHAR(MAX) = '0001,0011,0101,0101,0101'
SELECT CONVERT(binary(4), VALUE, 2) , VALUE FROM STRING_SPLIT( #agg , ',')
DECLARE #sum AS BIGINT = 0
DECLARE #mul AS BIGINT = 0xffffffff
SELECT #sum |= v
, #mul &= v
FROM STRING_SPLIT( #agg , ',')
CROSS APPLY (VALUES (CONVERT(binary(4), VALUE, 2))) _(v)
PRINT FORMAT(#sum,'X8')
PRINT FORMAT(#mul,'X8')
Prints
VALUE
---------- ------------
0x00010000 0001
0x00110000 0011
0x01010000 0101
0x01010000 0101
0x01010000 0101
01110000
00010000
In more complex word you need:
CREATE OR ALTER FUNCTION dbo.BOR( #agg VARCHAR(MAX))
RETURNS BIGINT
AS
BEGIN
DECLARE #sum AS BIGINT = 0
SELECT #sum |= CONVERT(BIGINT, VALUE)
FROM STRING_SPLIT( #agg , ',')
RETURN #sum
END
GO
CREATE OR ALTER FUNCTION dbo.BAND( #agg VARCHAR(MAX))
RETURNS BIGINT
AS
BEGIN
DECLARE #mul AS BIGINT = 0xffffffffffffffff
SELECT #mul &= CONVERT(BIGINT, VALUE)
FROM STRING_SPLIT( #agg , ',')
RETURN #mul
END
GO
when using bitmap of payment periods
;WITH delayedPayment AS
(SELECT * FROM ( VALUES
( 123, 67, '2020-2-1')
,( 123, 67, '2020-4-1')
,( 123, 67, '2020-5-1')
,( 123, 67, '2020-6-1')
,( 123, 68, '2020-6-1') -- another agreement
,( 123, 67, '2020-12-1')
,( 456, 69, '2020-4-1')
,( 456, 69, '2020-8-1')
,( 456, 69, '2020-10-1')
,( 456, 69, '2020-11-1')) _(cuno, loan, missedDuedate)
)
, delayPattern AS
(SELECT cuno
, sum_months
, bor_months
, IIF( FORMAT( CAST(bor_months AS BIGINT), 'X16') LIKE '%111%', 'dalyad 3+ month in row', NULL) delayState
FROM (SELECT cuno
, SUM(POWER( 16.0, CONVERT( BIGINT, DATEDIFF( month, missedDuedate, '2020-12-1')))) sum_months
, dbo.BOR( STRING_AGG( CONVERT( BIGINT, POWER( 16.0, DATEDIFF( month, missedDuedate, '2020-12-1'))),',')) bor_months
FROM delayedPayment
GROUP BY cuno
) s
)
SELECT cuno
, FORMAT( CAST(sum_months AS BIGINT), 'X16') sum_months
, FORMAT( CAST(bor_months AS BIGINT), 'X16') bor_months
, delayState
FROM delayPattern
cuno sum_months bor_months delayState
123 00000*10112*000001 00000*10111*000001 dalyad 3+ month in row
456 0000000100010110 0000000100010110 NULL
But sometimes just one need to think and you can do it with SUM
, delayPattern AS -- optimal
(SELECT cuno
, bor_months
, IIF( FORMAT( CAST(bor_months AS BIGINT), 'X16') LIKE '%111%', 'dalyad 3+ month in row', NULL) delayState
FROM (SELECT cuno
, SUM(POWER( 16.0, missedmonth)) bor_months
FROM ( SELECT DISTINCT cuno
, missedmonth
FROM delayedPayment
CROSS APPLY (VALUES ( DATEDIFF( month, missedDuedate, '2020-12-1'))) _(missedmonth)
GROUP BY cuno, missedmonth
) ss
GROUP BY cuno
) s
)
SELECT cuno
, FORMAT( CAST(bor_months AS BIGINT), 'X16') bor_months
, delayState
FROM delayPattern
Will print
cuno bor_months delayState
123 0000010111000001 dalyad 3+ month in row
456 0000000100010110 NULL
NOTE: I am using HEX format and POWER(16.0, X) , just to be lazy, POWER(2.0, X) will be correct, but then you need bin->string formatter. Something like this:
CREATE OR ALTER FUNCTION dbo.toBinaryString(#p INT)
RETURNS VARCHAR(24)
AS
BEGIN
RETURN REVERSE(REPLACE( REPLACE(
REPLACE( REPLACE( REPLACE( REPLACE(
REPLACE( REPLACE( REPLACE( REPLACE(
REPLACE( REPLACE( REPLACE( REPLACE(
REPLACE( REPLACE( REPLACE( REPLACE( FORMAT(#p,'X8'),
'0', '....'), '1', '...x'),'2', '..x.'),'3', '..xx'),
'4', '.x..'), '5', '.x.x'),'6', '.xx.'),'7', '.xxx'),
'8', 'x...'), '9', 'x..x'),'A', 'x.x.'),'B', 'x.xx'),
'C', 'xx..'), 'D', 'xx.x'),'E', 'xxx.'),'F', 'xxxx'),
'.','0'),'x','1'))
END