Re: Null in the where-clause

Michael Walzl sez:
} Hello everybody,
}
} I've got a problem with the "null"-statement within the where-clause.
} I installed the postgres-server 7.2.1 on a Suse Linux machine.
} Then I imported an existing databasedump.
} But when I make the following query:
} select * from tbl_categories where categoryid=null;
} I get 0 rows as result, but there are several records, which
} corrsponds to my query.
} What could be the problem? Do I have to reinstall the server
} with a special parameter?

The problem is that null isn't equal to anything, including itself. While a
null value in a column is not equal to null, it IS NULL:

select * from tbl_categories where categoryid is null;

} Thanx in advance
} Michael Walzl
--Greg