BINARY CHECKSUM

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BINARY CHECKSUM

Sriram-288748

SSCrazy

Points: 2874
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April 27, 2009 at 9:19 pm

#208881

Comments posted to this topic are about the item BINARY CHECKSUM
Sriram

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Ronald H SSCarpal Tunnel Points: 4053 More actions · Answer 1

Anyone who still uses text variables should be shot, especially because it makes me read the question wrong.

Ronald HensbergenHelp us, help yourself... Post data so we can read and use it: http://www.sqlservercentral.com/articles/Best+Practices/61537/-------------------------------------------------------------------------2+2=5 for significant large values of 2

Chad Crawford SSChampion Points: 11610 More actions · Answer 2

Hey Ronald - do you have a statistics background? I just noticed your sig line and it reminded me of an old statistician joke... 🙂

john.arnott SSChampion Points: 11882 More actions · Answer 3

Like Ronald, I doubt I'll have much use for a "text" datatype, but we do have XML in our databases so this QOD was valuable to me in pointing out that non-comparable datatypes are ignored. This script is modified from the original QOD to show the danger of depending on checksum or binary_checksum to flag certain changes.

Declare @FirstCksum int

CREATE TABLE #myTable (column1 xml,column2 int);

INSERT INTO #myTable VALUES ('',109);

select * from #mytable

SELECT @FirstCksum = BINARY_CHECKSUM(*) from #myTable;

update #myTable set column1='values' where column2 = 109

select * from #mytable

SELECT Case when BINARY_CHECKSUM(*) = @FirstCksum

then 'No Change'

else 'Table Modified'

end as TableChanged

from #myTable;

DROP TABLE #myTableYes, it returns "No Change" because only the int column is considered by the function.