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Asked: 2026-05-13T11:03:11+00:00

Today I found a strange problem that is I have a Table With a

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Today I found a strange problem that is I have a Table With a Nullable Column and I tried to use following Query

SELECT *
Id,
MyNCol,
FROM dbo.[MyTable]
WHERE MyNCol <> ‘MyValue’

And Expecting it to return all rows not having ‘MyValue’ value in Field MyNCol. But its not returning all those Rows Containing NULL in above specified Column(MyNCol).
So I have to Rewrite my query to

SELECT *
Id,
MyNCol,
FROM dbo.[MyTable]
WHERE MyNCol <> ‘MyValue’ OR MyNCol IS NULL

Now My question is why is it why the first query is not sufficient to perform what i desire. 🙁

Regards
Mubashar

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1 Answer

  1. Editorial Team

    Look into the behaviour of “ANSI NULLs”.

    Standardly, NULL != NULL. You can change this behaviour by altering the ANSI NULLS enabled property on your database, but this has far ranging effects on column storage and query execution. Alternatively, you can use the SET ANSI_NULLS statement in your SQL script.

    MSDN Documentation for SQL Server 2008 is here:
    SET ANSI_NULLS (Transact-SQL)

    Pay particular attention to the details of how comparisons are performed – even when setting ANSI_NULLS OFF, column to column comparisons may not behave as you intended. It is best practice to always use IS NULL and IS NOT NULL.

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