use IS NULL or IS NOT NULL to compare NULL values because they are simply unknown.
SELECT name
from products p
WHERE backorder IS NULL OR backorder <> 2
- SQLFiddle Demo
-
SQLFiddle Demo (added some records)
-
Working with NULL Values
use IS NULL or IS NOT NULL to compare NULL values because they are simply unknown.
SELECT name
from products p
WHERE backorder IS NULL OR backorder <> 2
SQLFiddle Demo (added some records)
Working with NULL Values