How to store and read bits from a session value called Context_Info.
SET Context_Info 0xFF;
-- bitindex is the value of the bit you want to get for example 7 is a value of 64 or 0x40
-- CONVERT(tinyint,bitindex value) & SUBSTRING(Context_Info(),byteoffset+1, 1)
select CONVERT(tinyint,0x01) & SUBSTRING(Context_Info(),1,1) AS '1',
CONVERT(tinyint,0x02) & SUBSTRING(Context_Info(),1,1) AS '2',
CONVERT(tinyint,0x04) & SUBSTRING(Context_Info(),1,1) AS '4',
CONVERT(tinyint,0x08) & SUBSTRING(Context_Info(),1,1) AS '8',
CONVERT(tinyint,0x10) & SUBSTRING(Context_Info(),1,1) AS '16',
CONVERT(tinyint,0x20) & SUBSTRING(Context_Info(),1,1) AS '32',
CONVERT(tinyint,0x40) & SUBSTRING(Context_Info(),1,1) AS '64',
CONVERT(tinyint,0x80) & SUBSTRING(Context_Info(),1,1) AS '128'
You can also store strings in it.
DECLARE @MyStatus VARBINARY(128);
SET @MyStatus = CAST('TEST' AS VARBINARY(128));
SET Context_Info @MyStatus;
SELECT CAST(Context_Info() AS VARCHAR)
-- Or substring :D
SELECT CAST(SUBSTRING(CONTEXT_INFO(), 1, 4) AS VARCHAR)
This Context_Info value could be useful to store a value for the session and change the control flow of a trigger.
