Description
When using an "is not" filter operator, the query does not return results where the field is empty or null. Also the operators "is different from" or "same as" exclude null values from comparisons.
Steps to Reproduce
1) Login an instance containing demo data
2) Navigate to User Administration > Users
3) Apply the following filters to the users list
• Company -- is not -- Acer
• User ID -- is -- admin
4) Click Run
Observe no records are returned, because users with no Company assigned do not satisfy the filter on company field set to Acer.
Workaround
This is expected behaviour for modern databases such as MySQL, SQL Server, and Oracle. The way the "not equal to" operator is behaving in the SN platform is congruent with standards-compliant SQL dialect.
Additional information on the SQL operator can be found in the stackoverflow article Not equal <> != operator on NULL
The query will need to have two conditions in OR: <field> is not <value> OR <field> is empty.
Related Problem: PRB659408