Question

I have a table with a column called status of type smallint and accepts null. Sql server 2000.

My data contains mostly 2 in that field, but also 0 and null.

When I do

select *
from table
 where status <> 2

I don’t get all the proper records (where status is null or 0). Any idea why this is happening and how to correct? Shouldn’t <> give me everything other than 2?

Answer 1

select *
from table
 where ISNULL(status, 1) <> 2

NULL doesn’t compare: so remove it.

Your example is the “common mistake” on Wikipedia too…