Example of BitField in SQL / TSQL / SQLServer

BitField.SQL

CREATE TABLE [dbo].[testBF](
    [field1] [varchar](max) NOT NULL,
    [field2] [varchar](max) NOT NULL,
    [bitfield] [int] NOT NULL CONSTRAINT [DF_testBF_bitfield]  DEFAULT ((0))
) ON [PRIMARY]

INSERT INTO testBF(field1,field2)
VALUES ('F1start1','F2start1');

INSERT INTO testBF(field1,field2)
VALUES ('F1start2','F2start2');

INSERT INTO testBF(field1,field2)
VALUES ('F1start3','F2start3') ;

SELECT field1, field2,
       CASE WHEN (bitfield & 1) = 1 THEN 'field1 mod' ELSE 'field1 same' END,
       CASE WHEN (bitfield & 2) = 2 THEN 'field2 mod' ELSE 'field2 same' END
FROM testBF

SELECT field1, field2,
        CASE WHEN (bitfield & 1) != 0 THEN 1 ELSE 0 END AS [field1flag],
        CASE WHEN (bitfield & 2) != 0 THEN 1 ELSE 0 END AS [field2flag]
FROM testBF

UPDATE testBF 
SET field1 = 'f1new', bitfield = bitfield | 1
WHERE field1 = 'F1start1'

UPDATE testBF 
SET field2 = 'f2new', bitfield = bitfield | 2
where field1 = 'F1start2'

SELECT field1, field2,
       CASE WHEN (bitfield & 1) = 1 THEN 'field1 mod' ELSE 'field1 same' END,
       CASE WHEN (bitfield & 2) = 2 THEN 'field2 mod' ELSE 'field2 same' END
FROM testBF

SELECT field1, field2,
        CASE WHEN (bitfield & 1) != 0 THEN 1 ELSE 0 END AS [field1flag],
        CASE WHEN (bitfield & 2) != 0 THEN 1 ELSE 0 END AS [field2flag]
FROM testBF

See this question on SO http://stackoverflow.com/a/9302106/215752