What's the difference between equality (=) and inequality (<>) on BIT field in SQL Server?

All we need is an easy explanation of the problem, so here it is.

Is there difference between WHERE [BitField] = 1 and WHERE [BitField] <> 0?

They seem logically equivalent.

SQL Server, however, disagrees and creates slightly different execution plans. (Which is bad because the second form doesn’t use existing indexes very effectively.)

Am I missing something, or it is just the way inequality operators behave?

How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

Method 1

They seem logically equivalent.

They are. Even with ANSI_NULLS OFF "a SELECT statement that uses WHERE column_name <> XYZ_value returns all rows that are not XYZ_value and that are not NULL."

I found an old feedback item for this here, you can go vote for it.

Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂

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